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GeneReviews, an international point-of-care resource for busy clinicians,provides clinically relevant and medically actionable information for inherited conditionsin a standardized journal-style format, covering diagnosis, management, andgenetic counseling for patients and their families. Each chapter inGeneReviews iswritten by one or more experts on the specific condition or disease and goes through arigorous editing andpeerreview process before being published online.

GeneReviews currently comprises 932 chapters and has more than ten million users annually.

The two general formats forGeneReviews are: chapters focused on a singlegene orphenotype (~95%) and overviews summarizing causes of common genetic conditions(e.g., genetic hearing loss, Alzheimer disease) (~5%).

To ensure continuing relevant and medically actionable content, eachGeneReviews chapter isupdated every four to five years (or as needed) by theauthor(s) in a formal and comprehensive process curated by theGeneReviewseditors. Additionalrevisions may occur morefrequently as needed to reflect significant changes in clinically relevant information.

Genetic counseling and testing terms used inGeneReviews are hyperlinkedto definitions in theGeneReviewsGlossary.Resource Materials include additional information on keygenetics concepts used inGeneReviews.

GeneReviews are indexed in PubMed.

Note: For a variety of reasons, GeneReviews occasionally removes chapters from the active website. Clickhere for a list of retired chapters.

GeneReviews by Title

1 ·3 ·7 ·15 ·16 ·17 ·21 ·22 ·A ·B ·C ·D ·E ·F ·G ·H ·I ·J ·K ·L ·M ·N ·O ·P ·R ·S ·T ·U ·V ·W ·X ·Y ·Z

• 1

• 1q21.1 Recurrent Deletion
  Rose Guo and Chad R Haldeman-Englert.
  Initial Posting: February 24, 2011; Last Update: February 1, 2024.

• 3

• 3-Hydroxyisobutyryl-CoA Hydrolase Deficiency
  Jose Abdenur and Rebekah Barrick.
  Initial Posting: November 20, 2025.
• 3-M Syndrome
  Rhoda Akilapa, Melita Irving, and Muriel Holder-Espinasse.
  Initial Posting: March 25, 2002; Last Update: February 27, 2025.
• 3q29 Recurrent Deletion
  Jennifer Gladys Mulle, Michael J Gambello, Rossana Sanchez Russo, Melissa M Murphy, T Lindsey Burrell, Cheryl Klaiman, Stormi White, Celine A Saulnier, Elaine F Walker, Joseph F Cubells, Sarah Shultz, and Longchuan Li.
  Initial Posting: September 22, 2016; Last Update: July 1, 2021.

• 7

• 7q11.23 Duplication Syndrome
  Carolyn B Mervis, Colleen A Morris, Bonita P Klein-Tasman, Shelley L Velleman, and Lucy R Osborne.
  Initial Posting: November 25, 2015; Last Update: March 25, 2021.

• 15

• 15q13.3 Recurrent Deletion
  Bregje WM van Bon, Heather C Mefford, Bert BA de Vries, and Christian P Schaaf.
  Initial Posting: December 23, 2010; Last Update: November 17, 2022.

• 16

• 16p11.2 Recurrent Deletion
  Cora M Taylor, Rebecca Smith, Christopher Lehman, Marissa W Mitchel, Kaitlyn Singer, W Curtis Weaver, and Wendy Chung.
  Initial Posting: September 22, 2009; Last Update: October 28, 2021.
• 16p12.2 Recurrent Deletion
  Santhosh Girirajan, Lucilla Pizzo, John Moeschler, and Jill Rosenfeld.
  Initial Posting: February 26, 2015; Last Update: September 13, 2018.

• 17

• 17q12 Recurrent Duplication
  Heather Mefford.
  Initial Posting: February 25, 2016; Last Revision: January 13, 2022.
• 17q12 Recurrent Deletion Syndrome
  Marissa W Mitchel, Daniel Moreno-De-Luca, Scott M Myers, Rebecca V Levy, Stefanie Turner, David H Ledbetter, and Christa L Martin.
  Initial Posting: December 8, 2016; Last Revision: August 14, 2025.

• 21

• 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia
  Saroj Nimkarn, Prasanna K Gangishetti, Mabel Yau, and Maria I New.
  Initial Posting: February 26, 2002; Last Update: February 4, 2016.

• 22

• 22q11.2 Deletion Syndrome
  Donna M McDonald-McGinn, Heather S Hain, Beverly S Emanuel, and Elaine H Zackai.
  Initial Posting: September 23, 1999; Last Revision: May 8, 2025.

• A

• AARS2-Related Disorder
  Tomasz Chmiela and Zbigniew K Wszolek.
  Initial Posting: October 31, 2024.
• ACTG2 Visceral Myopathy
  Pranjali K Bhagwat and Michael F Wangler.
  Initial Posting: June 11, 2015; Last Update: May 6, 2021.
• ADAMTSL4-Related Eye Disorders
  Eyvind Rødahl, Anne Elisabeth Christensen Mellgren, Nils-Erik Boonstra, and Per Morten Knappskog.
  Initial Posting: February 16, 2012; Last Revision: July 9, 2020.
• ADCY5-Related Movement Disorder
  Kathryn Yang and Darius Ebrahimi-Fakhari.
  Initial Posting: December 18, 2014; Last Update: June 26, 2025.
• ADNP-Related Helsmoortel-Van der Aa Syndrome
  Lusine Harutyunyan, R Frank Kooy, Claudio Peter D'Incal, and Anke Van Dijck.
  Initial Posting: April 7, 2016; Last Update: August 21, 2025.
• AFG3L2-Related Neurologic Disorders
  Giulia Coarelli and Charlotte Mouraux.
  Initial Posting: May 17, 2011; Last Update: September 18, 2025.
• AIP Familial Isolated Pituitary Adenomas
  Márta Korbonits and Laura C Hernández-Ramírez.
  Initial Posting: June 21, 2012; Last Revision: November 20, 2025.
• ALK-Related Neuroblastic Tumor Susceptibility
  Emily G Greengard, Melissa R Perrino, and Julie R Park.
  Initial Posting: January 5, 2010; Last Update: May 23, 2024.
• ALPK1-Related Autoinflammatory Disease
  Christina Kozycki, Dan Kastner, Laryssa Huryn, Shilpa Kodati, and Blake M Warner.
  Initial Posting: June 27, 2024.
• ALS2-Related Disorder
  Richard W Orrell.
  Initial Posting: October 21, 2005; Last Update: May 13, 2021.
• ANKRD17-Related Neurodevelopmental Syndrome
  Abigail Sveden, Christopher T Gordon, Jeanne Amiel, and Maya Chopra.
  Initial Posting: December 22, 2022.
• ANKRD26-Related Thrombocytopenia
  Juliana Perez Botero, Stefanie N Dugan, and Matthew W Anderson.
  Initial Posting: June 21, 2018.
• ANO5-Related Muscle Disease
  Johanna Palmio, Sini Penttilä, and Manu Jokela.
  Initial Posting: November 29, 2012; Last Update: May 15, 2025.
• AP-4-Associated Hereditary Spastic Paraplegia
  Julian Alecu, Luca Schierbaum, and Darius Ebrahimi-Fakhari.
  Initial Posting: December 13, 2018; Last Update: February 6, 2025.
• APC-Associated Polyposis Conditions
  Timothy Yen, Peter P Stanich, Lisen Axell, and Swati G Patel.
  Initial Posting: December 18, 1998; Last Update: May 12, 2022.
• APOB-Related Familial Hypobetalipoproteinemia
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: May 13, 2021; Last Revision: September 9, 2021.
• ARID1B-Related Disorder
  Samantha A Vergano, Pleuntje J van der Sluijs, and Gijs Santen.
  Initial Posting: May 23, 2019.
• ARSACS
  Sascha Vermeer, Bart P van de Warrenburg, Erik-Jan Kamsteeg, Bernard Brais, and Matthis Synofzik.
  Initial Posting: December 9, 2003; Last Update: January 2, 2020.
• ASAH1-Related Disorders
  David A Dyment, Steffany AL Bennett, Jeffrey A Medin, and Thierry Levade.
  Initial Posting: March 29, 2018.
• ASPM Primary Microcephaly
  Alain Verloes, Séverine Drunat, and Sandrine Passemard.
  Initial Posting: April 2, 2020.
• ASXL3-Related Disorder
  Meena Balasubramanian and Schaida Schirwani.
  Initial Posting: November 5, 2020.
• ATN1-Related Neurodevelopmental Disorder
  Chloe Whitton, Elizabeth Palmer, and Fowzan Alkuraya.
  Initial Posting: August 25, 2022.
• ATP1A3-Related Disorder
  Allison Brashear, Kathleen J Sweadner, Ihtsham Haq, Eleonora Napoli, and Laurie Ozelius.
  Initial Posting: February 7, 2008; Last Update: December 5, 2024.
• ATP6V0A2-Related Cutis Laxa
  Lionel Van Maldergem, William Dobyns, and Uwe Kornak.
  Initial Posting: March 19, 2009; Last Revision: March 16, 2023.
• ATP7A-Related Copper Transport Disorders
  Stephen G Kaler and Andrew T DiStasio.
  Initial Posting: May 9, 2003; Last Update: April 15, 2021.
• ATP8B1 Deficiency
  Laura N Bull, Raffaella Morotti, and James E Squires.
  Initial Posting: October 15, 2001; Last Update: September 9, 2021.
• Abetalipoproteinemia
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: October 25, 2018; Last Revision: May 19, 2022.
• Aceruloplasminemia
  Hiroaki Miyajima and Yasushi Hosoi.
  Initial Posting: August 12, 2003; Last Update: September 27, 2018.
• Achondrogenesis Type 1B
  Sheila Unger and Andrea Superti-Furga.
  Initial Posting: August 30, 2002; Last Revision: March 16, 2023.
• Achondroplasia
  Janet M Legare and Peggy Modaff.
  Initial Posting: October 12, 1998; Last Update: November 20, 2025.
• Achromatopsia
  Susanne Kohl, Herbert Jägle, Bernd Wissinger, and Ditta Zobor.
  Initial Posting: June 24, 2004; Last Update: September 20, 2018.
• Acid Sphingomyelinase Deficiency
  Melissa P Wasserstein and Edward H Schuchman.
  Initial Posting: December 7, 2006; Last Update: April 27, 2023.
• Activated PI3K Delta Syndrome
  Keith Sacco and Gulbu Uzel.
  Initial Posting: January 30, 2025.
• Acute Intermittent Porphyria
  Eliane Sardh and Michela Barbaro.
  Initial Posting: September 27, 2005; Last Update: February 8, 2024.
• Adenine Phosphoribosyltransferase Deficiency
  Vidar Orn Edvardsson, Amrik Sahota, and Runolfur Palsson.
  Initial Posting: August 30, 2012; Last Update: September 26, 2019.
• Adenosine Deaminase 2 Deficiency
  Ivona Aksentijevich, Natalia Sampaio Moura, and Karyl Barron.
  Initial Posting: August 8, 2019.
• Adenosine Deaminase Deficiency
  Michael Hershfield and Teresa Tarrant.
  Initial Posting: October 3, 2006; Last Update: March 7, 2024.
• Adult Refsum Disease
  Hans R Waterham, Ronald JA Wanders, and Bart P Leroy.
  Initial Posting: March 20, 2006; Last Update: September 30, 2021.
• Aicardi Syndrome
  V Reid Sutton and Ignatia B Van den Veyver.
  Initial Posting: June 30, 2006; Last Update: November 12, 2020.
• Aicardi-Goutières Syndrome
  Yanick J Crow.
  Initial Posting: June 29, 2005; Last Update: November 22, 2016.
• Alagille Syndrome
  Nancy B Spinner, Kathleen M Loomes, Ian D Krantz, and Melissa A Gilbert.
  Initial Posting: May 19, 2000; Last Update: January 4, 2024.
• Alexander Disease
  Siddharth Srivastava, Amy Waldman, and Sakkubai Naidu.
  Initial Posting: November 15, 2002; Last Update: November 12, 2020.
• Alkaptonuria
  Wendy J Introne, Monique Perry, and Marcus Chen.
  Initial Posting: May 9, 2003; Last Update: June 10, 2021.
• Allan-Herndon-Dudley Syndrome
  Catherine Sarret, Isabelle Oliver Petit, and Davide Tonduti.
  Initial Posting: March 9, 2010; Last Update: January 16, 2020.
• Alpha-1 Antitrypsin Deficiency
  James K Stoller, Vera Hupertz, and Loutfi S Aboussouan.
  Initial Posting: October 27, 2006; Last Revision: June 1, 2023.
• Alpha-Mannosidosis
  Can Ficicioglu and Karolina M Stepien.
  Initial Posting: October 11, 2001; Last Update: June 13, 2024.
• Alpha-Thalassemia X-Linked Intellectual Disability Syndrome
  Roger E Stevenson.
  Initial Posting: June 19, 2000; Last Update: May 28, 2020.
• Alpha-Thalassemia
  Hannah Tamary and Orly Dgany.
  Initial Posting: November 1, 2005; Last Revision: May 23, 2024.
• Alport Syndrome
  Kandai Nozu, Tomohiko Yamamura, and Tomoko Horinouchi.
  Initial Posting: August 28, 2001; Last Revision: August 14, 2025.
• Alström Syndrome
  Richard B Paisey, Rick Steeds, Tim Barrett, Denise Williams, Tarekegn Geberhiwot, and Meral Gunay-Aygun.
  Initial Posting: February 7, 2003; Last Update: June 13, 2019.
• Alzheimer Disease Overview
  Thomas D Bird.
  Initial Posting: October 23, 1998; Last Update: December 20, 2018.
• Amyotrophic Lateral Sclerosis Overview
  Nailah Siddique and Teepu Siddique.
  Initial Posting: March 23, 2001; Last Revision: September 28, 2023.
• Andersen-Tawil Syndrome
  Aravindhan Veerapandiyan, Jeffrey M Statland, and Rabi Tawil.
  Initial Posting: November 22, 2004; Last Update: June 7, 2018.
• Androgen Insensitivity Syndrome
  Bruce Gottlieb and Mark A Trifiro.
  Initial Posting: March 24, 1999; Last Update: May 11, 2017.
• Angelman Syndrome
  Aditi I Dagli, Jennifer Mathews, and Charles A Williams.
  Initial Posting: September 15, 1998; Last Revision: May 1, 2025.
• Apert Syndrome
  Tara L Wenger, Anne V Hing, and Kelly N Evans.
  Initial Posting: May 30, 2019.
• Arginase Deficiency
  Angela Sun, Eric A Crombez, and Derek Wong.
  Initial Posting: October 21, 2004; Last Update: May 28, 2020.
• Argininosuccinate Lyase Deficiency
  Sandesh CS Nagamani, Lindsay C Burrage, and Brendan Lee.
  Initial Posting: February 3, 2011; Last Update: August 14, 2025.
• Aromatic L-Amino Acid Decarboxylase Deficiency
  Nenad Blau, Toni S Pearson, Manju A Kurian, and Sarah H Elsea.
  Initial Posting: October 12, 2023; Last Revision: January 23, 2025.
• Arrhythmogenic Right Ventricular Cardiomyopathy Overview
  Elizabeth McNally, Heather MacLeod, and Lisa Dellefave-Castillo.
  Initial Posting: April 18, 2005; Last Update: May 11, 2023.
• Arterial Tortuosity Syndrome
  Bert Callewaert, Anne De Paepe, and Paul Coucke.
  Initial Posting: November 13, 2014; Last Revision: February 23, 2023.
• Arylsulfatase A Deficiency
  Natalia Gomez-Ospina.
  Initial Posting: May 30, 2006; Last Revision: April 25, 2024.
• Asparagine Synthetase Deficiency
  Majid Alfadhel and Ayman W El-Hattab.
  Initial Posting: September 20, 2018; Last Update: November 20, 2025.
• Aspartylglucosaminuria
  Kimberly Goodspeed, Xin Chen, and Michel Tchan.
  Initial Posting: January 18, 2024.
• Ataxia with Oculomotor Apraxia Type 2
  Maria-Ceu Moreira and Michel Koenig.
  Initial Posting: November 15, 2004; Last Update: July 12, 2018.
• Ataxia with Vitamin E Deficiency
  Markus Schuelke.
  Initial Posting: May 20, 2005; Last Update: March 16, 2023.
• Ataxia-Telangiectasia
  Stefanie Veenhuis, Nienke van Os, Corry Weemaes, Erik-Jan Kamsteeg, and Michèl Willemsen.
  Initial Posting: March 19, 1999; Last Update: October 5, 2023.
• Au-Kline Syndrome
  Ping-Yee Billie Au, Vanda McNiven, Lindsay Phillips, A Micheil Innes, and Antonie D Kline.
  Initial Posting: April 18, 2019; Last Update: February 1, 2024.
• Autoimmune Lymphoproliferative Syndrome
  Jack JH Bleesing, Chinmayee B Nagaraj, and Kejian Zhang.
  Initial Posting: September 14, 2006; Last Update: August 24, 2017.
• Autosomal Dominant Craniometaphyseal Dysplasia
  Ernst Reichenberger and I-Ping Chen.
  Initial Posting: August 27, 2007; Last Update: August 14, 2025.
• Autosomal Dominant Epilepsy with Auditory Features
  Roberto Michelucci, Elena Pasini, and Emanuela Dazzo.
  Initial Posting: April 20, 2007; Last Update: May 9, 2024.
• Autosomal Dominant Robinow Syndrome
  Maian Roifman, Han Brunner, Jamie Lohr, Juliana Mazzeu, and David Chitayat.
  Initial Posting: January 8, 2015; Last Revision: October 3, 2019.
• Autosomal Dominant Sleep-Related Hypermotor (Hyperkinetic) Epilepsy
  Hirokazu Kurahashi and Shinichi Hirose.
  Initial Posting: May 16, 2002; Last Update: March 23, 2023.
• Autosomal DominantTRPV4 Disorders
  Brett A McCray, Alice Schindler, Julie E Hoover-Fong, and Charlotte J Sumner.
  Initial Posting: May 15, 2014; Last Update: September 17, 2020.
• Autosomal Dominant Tubulointerstitial Kidney Disease –MUC1
  Anthony J Bleyer, Martina Živná, Kendrah Kidd, and Stanislav Kmoch.
  Initial Posting: August 15, 2013; Last Update: October 21, 2021.
• Autosomal Dominant Tubulointerstitial Kidney Disease –REN
  Martina Živná, Kendrah Kidd, Stanislav Kmoch, and Anthony J Bleyer.
  Initial Posting: April 5, 2011; Last Update: December 10, 2020.
• Autosomal Dominant Tubulointerstitial Kidney Disease –UMOD
  Anthony J Bleyer, Kendrah Kidd, Martina Živná, and Stanislav Kmoch.
  Initial Posting: January 12, 2007; Last Revision: December 23, 2021.
• Autosomal Recessive Congenital Ichthyosis
  Gabriele Richard.
  Initial Posting: January 10, 2001; Last Update: April 20, 2023.
• Autosomal Recessive Polycystic Kidney Disease – PKHD1
  Kathrin Burgmaier, Charlotte Gimpel, Franz Schaefer, and Max Liebau.
  Initial Posting: July 19, 2001; Last Update: April 4, 2024.
• Aymé-Gripp Syndrome
  Shivarajan Manickavasagam Amudhavalli, Randi Gadea, and Karen Gripp.
  Initial Posting: February 6, 2020.

• B

• BAP1 Tumor Predisposition Syndrome
  Robert Pilarski, Lindsey Byrne, Maria I Carlo, Helen Hanson, Colleen Cebulla, and Mohamed Abdel-Rahman.
  Initial Posting: October 13, 2016; Last Update: December 5, 2024.
• BCL11A-Related Intellectual Disability
  Angela Peron, Kimberley Bradbury, David H Viskochil, and Cristina Dias.
  Initial Posting: September 26, 2019.
• BRCA1- andBRCA2-Associated Hereditary Breast and Ovarian Cancer
  Nancie Petrucelli, Mary B Daly, and Tuya Pal.
  Initial Posting: September 4, 1998; Last Revision: March 20, 2025.
• BSCL2-Related Neurologic Disorders / Seipinopathy
  Daisuke Ito.
  Initial Posting: December 6, 2005; Last Update: May 24, 2018.
• Bachmann-Bupp Syndrome
  Caleb Bupp, Julianne Michael, Elizabeth VanSickle, Surender Rajasekaran, and André Stephan Bachmann.
  Initial Posting: August 25, 2022.
• Baller-Gerold Syndrome
  Lionel Van Maldergem, Juliette Piard, Lidia Larizza, and Lisa L Wang.
  Initial Posting: August 13, 2007; Last Update: April 19, 2018.
• Baraitser-Winter Cerebrofrontofacial Syndrome
  Alain Verloes, Séverine Drunat, Daniela Pilz, and Nataliya Di Donato.
  Initial Posting: November 19, 2015; Last Update: March 24, 2022.
• Bardet-Biedl Syndrome Overview
  RaeLynn Forsyth and Meral Gunay-Aygun.
  Initial Posting: July 14, 2003; Last Revision: March 23, 2023.
• Barth Syndrome
  Carlos Ferreira, Germaine Pierre, Reid Thompson, and Hilary Vernon.
  Initial Posting: October 9, 2014; Last Update: July 9, 2020.
• Beckwith-Wiedemann Syndrome
  Cheryl Shuman, Jennifer M Kalish, and Rosanna Weksberg.
  Initial Posting: March 3, 2000; Last Revision: September 21, 2023.
• Berardinelli-Seip Congenital Lipodystrophy
  Lionel Van Maldergem.
  Initial Posting: September 8, 2003; Last Update: December 8, 2016.
• Bestrophinopathies
  Ian M MacDonald, Thomas Lee, and Jessica Lawrence.
  Initial Posting: September 30, 2003; Last Update: July 16, 2020.
• Beta-Propeller Protein-Associated Neurodegeneration
  Allison Gregory, Manju A Kurian, Tobias Haack, Susan J Hayflick, and Penelope Hogarth.
  Initial Posting: February 16, 2017.
• Beta-Thalassemia
  Arielle L Langer.
  Initial Posting: September 28, 2000; Last Revision: February 8, 2024.
• Bietti Crystalline Dystrophy
  Mauricio Vargas, Amanda Mitchell, Paul Yang, and Richard Weleber.
  Initial Posting: April 12, 2012; Last Update: February 7, 2019.
• Biotin-Thiamine-Responsive Basal Ganglia Disease
  Brahim Tabarki, Amal Al-Hashem, Juan Darío Ortigoza-Escobar, Hind Alsharhan, and Majid Alfadhel.
  Initial Posting: November 21, 2013; Last Update: January 9, 2025.
• Biotinidase Deficiency
  Barry Wolf.
  Initial Posting: March 24, 2000; Last Update: May 25, 2023.
• Birt-Hogg-Dubé Syndrome
  Elke C Sattler and Ortrud K Steinlein.
  Initial Posting: February 27, 2006; Last Update: December 5, 2024.
• Blepharophimosis, Ptosis, and Epicanthus Inversus Syndrome
  Hannah Verdin, Charlotte Matton, and Elfride De Baere.
  Initial Posting: July 8, 2004; Last Update: March 10, 2022.
• Bloom Syndrome
  Katherine Langer, Christopher M Cunniff, and Nicole Kucine.
  Initial Posting: March 22, 2006; Last Update: October 12, 2023.
• Bohring-Opitz Syndrome
  Bianca Russell, Wen-Hann Tan, and John M Graham, Jr.
  Initial Posting: February 15, 2018.
• Branchiooculofacial Syndrome
  Chad R Haldeman-Englert, Angela E Lin, and Jeff M Milunsky.
  Initial Posting: May 31, 2011; Last Revision: August 14, 2025.
• Branchiootorenal Spectrum Disorder
  Richard JH Smith and Hela Azaiez.
  Initial Posting: March 19, 1999; Last Update: June 26, 2025.
• Brugada Syndrome
  Ramon Brugada, Oscar Campuzano, Georgia Sarquella-Brugada, Pedro Brugada, Josep Brugada, and Kui Hong.
  Initial Posting: March 31, 2005; Last Update: August 25, 2022.
• Bryant-Li-Bhoj Neurodevelopmental Syndrome
  Laura Bryant and Elizabeth Bhoj.
  Initial Posting: September 28, 2023.

• C

• C3 Glomerulopathy
  Bertha Martín and Richard JH Smith.
  Initial Posting: July 20, 2007; Last Update: April 5, 2018.
• C9orf72 Frontotemporal Dementia and/or Amyotrophic Lateral Sclerosis
  Helena Gossye, Sebastiaan Engelborghs, Christine Van Broeckhoven, and Julie van der Zee.
  Initial Posting: January 8, 2015; Last Update: December 17, 2020.
• CACNA1C-Related Disorders
  Carlo Napolitano and Silvia G Priori.
  Initial Posting: February 15, 2006; Last Revision: September 18, 2025.
• CADASIL
  Remco J Hack, Julie Rutten, and Saskia AJ Lesnik Oberstein.
  Initial Posting: March 15, 2000; Last Update: March 14, 2019.
• CASK Disorders
  Ute Moog and Kerstin Kutsche.
  Initial Posting: November 26, 2013; Last Update: May 21, 2020.
• CDC73-Related Disorders
  Catherine M Skefos, Steven G Waguespack, Nancy D Perrier, and Mimi I Hu.
  Initial Posting: December 31, 2008; Last Update: September 21, 2023.
• CDK13-Related Disorder
  Bret Bostwick.
  Initial Posting: January 31, 2019.
• CDKL5 Deficiency Disorder
  Tim A Benke, Scott Demarest, Katie Angione, Jenny Downs, Helen Leonard, Jacinta Saldaris, Eric D Marsh, Heather Olson, and Isabel Haviland.
  Initial Posting: April 11, 2024; Last Revision: May 1, 2025.
• CDKN2A Cancer Predisposition
  Michelle F Jacobs, Andrea M Murad, Nicole D Cho, Kelly B Cha, Elena M Stoffel, and Tobias Else.
  Initial Posting: July 17, 2025.
• CEBPA-Associated Familial Acute Myeloid Leukemia (AML)
  Kiran Tawana and Jude Fitzgibbon.
  Initial Posting: October 21, 2010; Last Update: February 18, 2021.
• CETP-Related Hyperalphalipoproteinemia
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: May 8, 2025.
• CHCHD10-Related Disorders
  Samira Ait-El-Mkadem Saadi, Annabelle Chaussenot, Sylvie Bannwarth, Cécile Rouzier, and Véronique Paquis-Flucklinger.
  Initial Posting: July 1, 2015; Last Update: May 27, 2021.
• CHD2-Related Neurodevelopmental Disorders
  Gemma L Carvill and Heather C Mefford.
  Initial Posting: December 10, 2015; Last Update: January 21, 2021.
• CHD4 Neurodevelopmental Disorder
  Karin Weiss and Katherine Lachlan.
  Initial Posting: September 3, 2020.
• CHD7 Disorder
  Conny M van Ravenswaaij-Arts, Meg Hefner, Kim Blake, and Donna M Martin.
  Initial Posting: October 2, 2006; Last Revision: August 14, 2025.
• CHD8-Related Neurodevelopmental Disorder with Overgrowth
  Marissa W Mitchel, Scott M Myers, Alexis R Heidlebaugh, Cora M Taylor, Hannah Rea, Emily Neuhaus, Evangeline C Kurtz-Nelson, Rachel Earl, Raphael Bernier, David H Ledbetter, Christa L Martin, and Evan E Eichler.
  Initial Posting: October 27, 2022.
• CHEK2-Related Cancer Predisposition
  Helen Hanson, Tuya Pal, Marc Tischkowitz, and Douglas Stewart.
  Initial Posting: May 29, 2025.
• CHKB-Related Muscular Dystrophy
  Sophelia HS Chan and Ichizo Nishino.
  Initial Posting: March 30, 2023.
• CHMP2B Frontotemporal Dementia
  Peter Roos, Ida E Holm, Jørgen E Nielsen, Troels T Nielsen, Jeremy M Brown, Peter Johannsen, and Adrian M Isaacs.
  Initial Posting: August 23, 2007; Last Update: July 2, 2020.
• CLCN2-Related Leukoencephalopathy
  Rogier Min, Christel Depienne, Frederic Sedel, Truus EM Abbink, and Marjo S van der Knaap.
  Initial Posting: November 5, 2015; Last Update: May 20, 2021.
• CLCN4-Related Neurodevelopmental Disorder
  Elizabeth Emma Palmer, Matthew Huu Nguyen, Caitlin Forwood, and Vera Kalscheuer.
  Initial Posting: December 16, 2021.
• CLCN7-Related Osteopetrosis
  Cristina Sobacchi, Anna Villa, Ansgar Schulz, and Uwe Kornak.
  Initial Posting: February 12, 2007; Last Update: January 20, 2022.
• CLPB Deficiency
  Saskia B Wortmann and Ron A Wevers.
  Initial Posting: November 22, 2016; Last Update: March 10, 2022.
• COL1A1- andCOL1A2-Related Osteogenesis Imperfecta
  Mercedes Rodriguez Celin, Robert D Steiner, and Donald Basel.
  Initial Posting: January 28, 2005; Last Update: May 29, 2025.
• COL4A1-Related Disorders
  Emmanuelle Plaisier and Pierre Ronco.
  Initial Posting: June 25, 2009; Last Update: July 7, 2016.
• COMP-Related Pseudoachondroplasia
  Michael D Briggs and Michael J Wright.
  Initial Posting: August 20, 2004; Last Update: November 30, 2023.
• CSF1R-Related Disorder
  Jaroslaw Dulski, Christina Sundal, and Zbigniew K Wszolek.
  Initial Posting: August 30, 2012; Last Update: April 4, 2024.
• CTCF-Related Disorder
  Hannah Gabriela Valverde de Morales, Hsiao-Lin Wang, Kathryn Garber, Victor Corces, and Hong Li.
  Initial Posting: April 25, 2024.
• CSNK2B-Related Neurodevelopmental Disorder
  Natalie Lippa, Maureen Mulhern, Michelle Ernst Florido, Chelsea Earley, and Tristan T Sands.
  Initial Posting: September 5, 2024.
• CTDP1-Related Congenital Cataracts, Facial Dysmorphism, and Neuropathy
  Luba Kalaydjieva and Teodora Chamova.
  Initial Posting: March 2, 2010; Last Update: October 13, 2022.
• CTNNB1 Neurodevelopmental Disorder
  Stephanie KL Ho, Mandy HY Tsang, Mianne Lee, Shirley SW Cheng, Ho-ming Luk, Ivan FM Lo, and Brian HY Chung.
  Initial Posting: May 19, 2022.
• CYLD Cutaneous Syndrome
  Anna Dubois and Neil Rajan.
  Initial Posting: April 16, 2020.
• Caffey Disease
  Andrea Guerin, Lucie Dupuis, and Roberto Mendoza-Londono.
  Initial Posting: August 2, 2012; Last Update: May 23, 2024.
• Calpainopathy
  Corrado Angelini.
  Initial Posting: May 10, 2005; Last Revision: May 1, 2025.
• Campomelic Dysplasia
  Sheila Unger, Gerd Scherer, and Andrea Superti-Furga.
  Initial Posting: July 31, 2008; Last Revision: April 6, 2023.
• Camurati-Engelmann Disease
  Stephanie E Wallace and William R Wilcox.
  Initial Posting: June 25, 2004; Last Update: August 31, 2023.
• Canavan Disease
  Amanda Nagy, Annette E Bley, and Florian Eichler.
  Initial Posting: September 16, 1999; Last Update: December 21, 2023.
• Cantú Syndrome
  Dorothy K Grange, Colin G Nichols, and Gautam K Singh.
  Initial Posting: October 2, 2014; Last Update: October 1, 2020.
• Capillary Malformation-Arteriovenous Malformation Syndrome
  Pinar Bayrak-Toydemir and David A Stevenson.
  Initial Posting: February 22, 2011; Last Update: September 12, 2019.
• Carbonic Anhydrase VA Deficiency
  Clara van Karnebeek and Johannes Häberle.
  Initial Posting: April 2, 2015; Last Update: August 26, 2021.
• Cardiofaciocutaneous Syndrome
  Katherine A Rauen.
  Initial Posting: January 18, 2007; Last Update: February 9, 2023.
• Carney Complex
  Constantine A Stratakis.
  Initial Posting: February 5, 2003; Last Update: September 21, 2023.
• Carnitine Palmitoyltransferase 1A Deficiency
  Kristen Lee, Amanda Pritchard, and Ayesha Ahmad.
  Initial Posting: July 27, 2005; Last Update: February 20, 2025.
• Carnitine Palmitoyltransferase II Deficiency
  Thomas Wieser.
  Initial Posting: August 27, 2004; Last Revision: January 3, 2019.
• Cartilage-Hair Hypoplasia – Anauxetic Dysplasia Spectrum Disorders
  Outi Mäkitie and Svetlana Vakkilainen.
  Initial Posting: March 15, 2012; Last Revision: August 7, 2025.
• Carnitine-Acylcarnitine Translocase Deficiency
  J Andres Morales Corado, Chung U Lee, and Gregory M Enns.
  Initial Posting: July 21, 2022.
• Catecholaminergic Polymorphic Ventricular Tachycardia
  Carlo Napolitano, Andrea Mazzanti, Raffaella Bloise, and Silvia G Priori.
  Initial Posting: October 14, 2004; Last Update: June 23, 2022.
• Celiac Disease
  Annette K Taylor, Benjamin Lebwohl, Cara L Snyder, and Peter HR Green.
  Initial Posting: July 3, 2008; Last Update: January 31, 2019.
• Cerebrotendinous Xanthomatosis
  Antonio Federico and Gian Nicola Gallus.
  Initial Posting: July 16, 2003; Last Revision: November 14, 2024.
• Char Syndrome
  Bruce D Gelb.
  Initial Posting: August 15, 2003; Last Update: May 21, 2020.
• Charcot-Marie-Tooth Hereditary Neuropathy Overview
  Thomas D Bird.
  Initial Posting: September 28, 1998; Last Revision: November 20, 2025.
• Chediak-Higashi Syndrome
  Camilo Toro, Marie Morimoto, May Christine Malicdan, David R Adams, and Wendy J Introne.
  Initial Posting: March 3, 2009; Last Update: December 21, 2023.
• Cherubism
  Anne Morice, Natacha Kadlub, and Amélie Coudert.
  Initial Posting: February 26, 2007; Last Update: March 20, 2025.
• Childhood Ataxia with Central Nervous System Hypomyelination / Vanishing White Matter
  Marjo S van der Knaap, Anne Fogli, Odile Boespflug-Tanguy, Truus EM Abbink, and Raphael Schiffmann.
  Initial Posting: February 20, 2003; Last Update: April 4, 2019.
• Chondrodysplasia with Congenital Joint Dislocations,CHST3-Related
  Andrea Superti-Furga and Sheila Unger.
  Initial Posting: September 1, 2011; Last Update: August 1, 2024.
• Chondrodysplasia Punctata 1, X-Linked
  Nancy E Braverman, Michael B Bober, Nicola Brunetti-Pierri, and Sharon F Suchy.
  Initial Posting: April 22, 2008; Last Update: October 15, 2020.
• Chondrodysplasia Punctata 2, X-Linked
  Smitha Kumble and Ravi Savarirayan.
  Initial Posting: May 31, 2011; Last Update: January 9, 2020.
• Choroideremia
  Ian M MacDonald, Stacey Hume, Yi Zhai, and Manlong Xu.
  Initial Posting: February 21, 2003; Last Update: March 4, 2021.
• Christianson Syndrome
  Eric M Morrow and Matthew F Pescosolido.
  Initial Posting: January 11, 2018; Last Revision: September 18, 2025.
• Chronic Granulomatous Disease
  Jennifer W Leiding and Steven M Holland.
  Initial Posting: August 9, 2012; Last Update: April 21, 2022.
• Chylomicron Retention Disease
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: March 24, 2022.
• Citrin Deficiency
  Yuan-Zong Song, Kimihiko Oishi, and Takeyori Saheki.
  Initial Posting: September 16, 2005; Last Update: March 20, 2025.
• Citrullinemia Type I
  Shane C Quinonez and Kristen N Lee.
  Initial Posting: July 7, 2004; Last Update: August 18, 2022.
• Classic Ehlers-Danlos Syndrome
  Fransiska Malfait, Sofie Symoens, and Delfien Syx.
  Initial Posting: May 29, 2007; Last Update: February 1, 2024.
• Classic Galactosemia and Clinical Variant Galactosemia
  Gerard T Berry.
  Initial Posting: February 4, 2000; Last Update: March 11, 2021.
• Classic Isovaleric Acidemia
  Ulrike Mütze, Anna Reischl-Hajiabadi, and Stefan Kölker.
  Initial Posting: March 14, 2024.
• Classic Mowat-Wilson Syndrome
  Margaret P Adam, Jessie Conta, and Lora JH Bean.
  Initial Posting: March 28, 2007; Last Update: April 10, 2025.
• Cleidocranial Dysplasia Spectrum Disorder
  Keren Machol, Roberto Mendoza-Londono, and Brendan Lee.
  Initial Posting: January 3, 2006; Last Update: April 13, 2023.
• Cockayne Syndrome
  Vincent Laugel.
  Initial Posting: December 28, 2000; Last Update: August 29, 2024.
• Coffin-Siris Syndrome
  Samantha Schrier Vergano, Gijs Santen, Dagmar Wieczorek, and Naomichi Matsumoto.
  Initial Posting: April 4, 2013; Last Update: May 15, 2025.
• Cohen Syndrome
  Heng Wang, Marni J Falk, Christine Wensel, and Elias I Traboulsi.
  Initial Posting: August 29, 2006; Last Update: July 21, 2016.
• Cold-Induced Sweating Syndrome Including Crisponi Syndrome
  Angelika F Hahn and Per Morten Knappskog.
  Initial Posting: March 3, 2011; Last Update: August 12, 2021.
• Collagen VI-Related Dystrophies
  A Reghan Foley, Payam Mohassel, Sandra Donkervoort, Véronique Bolduc, and Carsten G Bönnemann.
  Initial Posting: June 25, 2004; Last Update: March 11, 2021.
• Complete Plasminogen Activator Inhibitor 1 Deficiency
  Meadow Heiman, Sweta Gupta, Magdalena Lewandowska, and Amy D Shapiro.
  Initial Posting: August 3, 2017; Last Update: February 23, 2023.
• Congenital Central Hypoventilation Syndrome
  Debra E Weese-Mayer, Casey M Rand, Ilya Khaytin, Susan M Slattery, Kai Lee Yap, Mary L Marazita, and Elizabeth M Berry-Kravis.
  Initial Posting: January 28, 2004; Last Update: January 28, 2021.
• Congenital Contractural Arachnodactyly
  Bert Callewaert.
  Initial Posting: January 23, 2001; Last Revision: July 14, 2022.
• Congenital Deafness with Labyrinthine Aplasia, Microtia, and Microdontia
  Jessica Ordonez and Mustafa Tekin.
  Initial Posting: September 20, 2012; Last Revision: August 14, 2025.
• Congenital Disorders of N-Linked Glycosylation and Multiple Pathway Overview
  Susan E Sparks and Donna M Krasnewich.
  Initial Posting: August 15, 2005; Last Update: January 12, 2017.
• Congenital Dyserythropoietic Anemia Type I
  Hannah Tamary and Orly Dgany.
  Initial Posting: April 21, 2009; Last Update: July 29, 2021.
• Congenital Erythropoietic Porphyria
  Angelika Erwin, Manisha Balwani, Robert J Desnick; Porphyrias Consortium of the NIH-Sponsored Rare Diseases Clinical Research Network.
  Initial Posting: September 12, 2013; Last Update: April 15, 2021.
• Congenital Fibrosis of the Extraocular Muscles Overview
  Mary C Whitman, Julie A Jurgens, David G Hunter, and Elizabeth C Engle.
  Initial Posting: April 27, 2004; Last Update: August 12, 2021.
• Congenital Insensitivity to Pain Overview
  Katherine Rose Schon, Alasdair Patrick John Parker, and Christopher Geoffrey Woods.
  Initial Posting: February 8, 2018; Last Revision: June 11, 2020.
• Congenital Mirror Movements
  Aurélie Méneret, Oriane Trouillard, Margaux Dunoyer, Christel Depienne, and Emmanuel Roze.
  Initial Posting: March 12, 2015; Last Update: September 24, 2020.
• Congenital Myasthenic Syndromes Overview
  Angela Abicht, Juliane S Müller, and Hanns Lochmüller.
  Initial Posting: May 9, 2003; Last Update: December 23, 2021.
• Congenital NAD Deficiency Disorder
  Paul Mark and Sally Dunwoodie.
  Initial Posting: July 27, 2023.
• Congenital Stromal Corneal Dystrophy
  Eyvind Rødahl, Per M Knappskog, Cecilie Bredrup, and Helge Boman.
  Initial Posting: November 25, 2008; Last Update: November 29, 2018.
• Cornelia de Lange Syndrome
  Matthew A Deardorff, Sarah E Noon, and Ian D Krantz.
  Initial Posting: September 16, 2005; Last Update: October 15, 2020.
• Costeff Syndrome
  Yair Anikster.
  Initial Posting: July 28, 2006; Last Update: April 30, 2020.
• Cranioectodermal Dysplasia
  Weizhen Tan, Angela Lin, and Kim Keppler-Noreuil.
  Initial Posting: September 12, 2013; Last Revision: December 15, 2022.
• Creatine Deficiency Disorders
  Saadet Mercimek-Andrews and Gajja S Salomons.
  Initial Posting: January 15, 2009; Last Revision: August 7, 2025.
• Cystic Fibrosis
  Adrienne Savant, Benjamin Lyman, Christine Bojanowski, and Jariya Upadia.
  Initial Posting: March 26, 2001; Last Revision: August 8, 2024.
• Cystinosis
  Galina Nesterova and William A Gahl.
  Initial Posting: March 22, 2001; Last Update: August 14, 2025.
• Cystinuria
  Andrea Spasiano, Jan Halbritter, and Pietro Manuel Ferraro.
  Initial Posting: November 20, 2025.
• Cytochrome P450 Oxidoreductase Deficiency
  Jan Idkowiak, Deborah Cragun, Robert J Hopkin, and Wiebke Arlt.
  Initial Posting: September 8, 2005; Last Update: August 3, 2017.

• D

• DBA Syndrome
  Colin Sieff.
  Initial Posting: June 25, 2009; Last Update: July 31, 2025.
• DCTN1-Related Neurodegeneration
  Jaroslaw Dulski, Takuya Konno, and Zbigniew Wszolek.
  Initial Posting: September 30, 2010; Last Update: August 5, 2021.
• DCX-Related Disorders
  Tobias Geis, Gökhan Uyanik, Ludwig Aigner, Sebastien Couillard-Despres, Jürgen Winkler, and Ute Hehr.
  Initial Posting: October 19, 2007; Last Update: June 5, 2025.
• DDX11-Related Cohesinopathy
  Ebba Alkhunaizi, Robert M Brosh, Jr, and David Chitayat.
  Initial Posting: June 6, 2019; Last Update: June 5, 2025.
• DDX3X-Related Neurodevelopmental Disorder
  Bethany Johnson-Kerner, Lot Snijders Blok, Lindsey Suit, Julian Thomas, Tjitske Kleefstra, and Elliott H Sherr.
  Initial Posting: August 27, 2020.
• DDX41-Associated Familial Myelodysplastic Syndrome and Acute Myeloid Leukemia
  Jane E Churpek and Kelcy Smith-Simmer.
  Initial Posting: October 28, 2021.
• DEPDC5-Related Epilepsy
  Stéphanie Baulac and Sara Baldassari.
  Initial Posting: September 29, 2016; Last Update: March 9, 2023.
• DFNA2 Nonsyndromic Hearing Loss
  Richard JH Smith and Michael Hildebrand.
  Initial Posting: April 4, 2008; Last Update: May 10, 2018.
• DICER1 Tumor Predisposition
  Kris Ann P Schultz, Douglas R Stewart, Junne Kamihara, Andrew J Bauer, Melissa A Merideth, Pamela Stratton, Laryssa A Huryn, Anne K Harris, Leslie Doros, Amanda Field, Ann G Carr, Louis P Dehner, Yoav Messinger, and D Ashley Hill.
  Initial Posting: April 24, 2014; Last Update: April 30, 2020.
• DLG4-Related Synaptopathy
  Zeynep Tümer, Thomas J Dye, Carlos Prada, Alexandre M White-Brown, Alex MacKenzie, and Amanda M Levy.
  Initial Posting: June 22, 2023.
• DNAJC6 Parkinson Disease
  Manju A Kurian and Lucia Abela.
  Initial Posting: May 13, 2021.
• DNMT1-Related Disorder
  Christopher J Klein.
  Initial Posting: February 16, 2012; Last Update: January 31, 2019.
• DRPLA
  Silvia Prades, PhD, Claudio Melo de Gusmao, MD, Silvia Grimaldi, MD, Yael Shiloh-Malawsky, MD, Thomas Felton, MS, CGC, and Henry Houlden, MD, PhD.
  Initial Posting: August 6, 1999; Last Update: September 21, 2023.
• DYNC1H1-Related Disorders
  Birk Möller, Antonietta Coppola, Heinz Jungbluth, and Hormos Salimi Dafsari.
  Initial Posting: March 21, 2024.
• DYRK1A Syndrome
  Bregje WM van Bon, Bradley P Coe, Bert BA de Vries, and Evan E Eichler.
  Initial Posting: December 17, 2015; Last Update: March 18, 2021.
• DYT-GNAL
  Angela B Deutschländer and Zbigniew K Wszolek.
  Initial Posting: January 3, 2019.
• DYT-TOR1A
  Laurie Ozelius and Naomi Lubarr.
  Initial Posting: April 14, 1999; Last Update: November 20, 2025.
• Danon Disease
  Matthew RG Taylor and Eric D Adler.
  Initial Posting: March 5, 2020; Last Revision: May 23, 2024.
• Deafness-Dystonia-Optic Neuronopathy Syndrome
  Lisbeth Tranebjærg.
  Initial Posting: February 6, 2003; Last Update: November 21, 2019.
• Dent Disease
  John C Lieske, Dawn S Milliner, Lada Beara-Lasic, Peter Harris, Andrea Cogal, and Elizabeth Abrash.
  Initial Posting: August 9, 2012; Last Update: December 14, 2017.
• Deoxyguanosine Kinase Deficiency
  Ayman W El-Hattab and Fernando Scaglia.
  Initial Posting: June 18, 2009; Last Update: February 9, 2023.
• Diabetes Mellitus, 6q24-Related Transient Neonatal
  Isabel Karen Temple and Deborah JG Mackay.
  Initial Posting: October 10, 2005; Last Update: September 13, 2018.
• Diastrophic Dysplasia
  Sheila Unger and Andrea Superti-Furga.
  Initial Posting: November 15, 2004; Last Revision: March 16, 2023.
• Diffuse Gastric and Lobular Breast Cancer Syndrome
  Rita Barbosa-Matos, Lilian Córdova, Kasmintan Schrader, and Carla Oliveira.
  Initial Posting: November 4, 2002; Last Update: October 10, 2024.
• Dihydrolipoamide Dehydrogenase Deficiency
  Shane C Quinonez and Jess G Thoene.
  Initial Posting: July 17, 2014; Last Revision: September 30, 2021.
• Dilated Cardiomyopathy Overview
  Ray E Hershberger and Elizabeth Jordan.
  Initial Posting: July 27, 2007; Last Revision: December 12, 2024.
• Disorders ofGNAS Inactivation
  Chad R Haldeman-Englert, Anna CE Hurst, and Michael A Levine.
  Initial Posting: October 26, 2017.
• Disorders of Intracellular Cobalamin Metabolism
  Jennifer L Sloan, Nuria Carrillo, David Adams, and Charles P Venditti.
  Initial Posting: February 25, 2008; Last Revision: December 16, 2021.
• Donnai-Barrow Syndrome
  Mauro Longoni, Sibel Kantarci, Dian Donnai, and Barbara R Pober.
  Initial Posting: August 28, 2008; Last Update: November 21, 2018.
• Dopamine Beta-Hydroxylase Deficiency
  Italo Biaggioni.
  Initial Posting: September 4, 2003; Last Update: September 26, 2024.
• Duane Syndrome
  Brenda J Barry, Mary C Whitman, David G Hunter, and Elizabeth C Engle.
  Initial Posting: May 25, 2007; Last Update: August 29, 2019.
• Duarte Variant Galactosemia
  Judith L Fridovich-Keil, Michael J Gambello, Rani H Singh, and J Daniel Sharer.
  Initial Posting: December 4, 2014; Last Revision: June 25, 2020.
• Dysferlinopathy
  Masashi Aoki and Toshiaki Takahashi.
  Initial Posting: February 5, 2004; Last Update: May 27, 2021.
• Dyskeratosis Congenita and Related Telomere Biology Disorders
  Sharon A Savage and Marena R Niewisch.
  Initial Posting: November 12, 2009; Last Revision: January 19, 2023.
• Dystrophic Epidermolysis Bullosa
  Anne W Lucky, Elena Pope, and Sarah Crawford.
  Initial Posting: August 21, 2006; Last Revision: August 7, 2025.
• Dystrophinopathies
  Basil T Darras, David K Urion, and Partha S Ghosh.
  Initial Posting: September 5, 2000; Last Revision: January 20, 2022.

• E

• EBF3 Neurodevelopmental Disorder
  Dhanya Lakshmi Narayanan, Kerstin Kutsche, and Katta M Girisha.
  Initial Posting: May 6, 2021.
• EED-Related Overgrowth
  Ana Sequerra Amram Cohen and William Thomas Gibson.
  Initial Posting: April 11, 2019; Last Update: May 8, 2025.
• EFEMP2-Related Cutis Laxa
  Bart Loeys, Anne De Paepe, and Zsolt Urban.
  Initial Posting: May 12, 2011; Last Revision: June 15, 2023.
• ELANE-Related Neutropenia
  David C Dale and Vahagn Makaryan.
  Initial Posting: June 17, 2002; Last Update: August 23, 2018.
• ELN-Related Cutis Laxa
  Bert L Callewaert and Zsolt Urban.
  Initial Posting: September 29, 2022.
• EMC10-Related Neurodevelopmental Disorder
  Muhammad Umair and Majid Alfadhel.
  Initial Posting: June 15, 2023.
• ENTPD1-Related Neurodevelopmental Disorder
  Daniel Calame and Isabella Herman.
  Initial Posting: June 1, 2023.
• EPB42-Related Hereditary Spherocytosis
  Theodosia A Kalfa and Amber H Begtrup.
  Initial Posting: March 13, 2014; Last Update: April 7, 2022.
• EPG5-Related Disorder
  Hormos Salimi Dafsari, Darius Ebrahimi-Fakhari, Afshin Saffari, Celine Deneubourg, Manolis Fanto, and Heinz Jungbluth.
  Initial Posting: October 13, 2022.
• ESCO2 Spectrum Disorder
  Hugo Vega, Miriam Gordillo, and Ethylin Wang Jabs.
  Initial Posting: April 18, 2006; Last Update: August 14, 2025.
• ETV6-Related Thrombocytopenia and Predisposition to Leukemia
  Bojana Pencheva, Jorge Di Paola, and Christopher C Porter.
  Initial Posting: November 19, 2020; Last Update: June 26, 2025.
• EXOC6B-Related Spondyloepimetaphyseal Dysplasia with Joint Laxity
  Gandham SriLakshmi Bhavani, Swati Singh, and Katta Mohan Girisha.
  Initial Posting: May 25, 2023; Last Revision: July 17, 2025.
• EXOSC3 Pontocerebellar Hypoplasia
  Frank Baas and Tessa van Dijk.
  Initial Posting: August 21, 2014; Last Update: September 24, 2020.
• EZH2-Related Overgrowth
  Sharon Ocansey and Katrina Tatton-Brown.
  Initial Posting: July 18, 2013; Last Revision: June 26, 2025.
• El-Hattab-Alkuraya Syndrome
  Mohammed Almannai, Dana Marafi, and Ayman W El-Hattab.
  Initial Posting: September 29, 2022.
• Ellis-van Creveld Syndrome
  Jorge Diogo Da Silva, Nataliya Tkachenko, and Ana Rita Soares.
  Initial Posting: October 26, 2023.
• Emanuel Syndrome
  Beverly S Emanuel, Elaine H Zackai, and Livija Medne.
  Initial Posting: April 20, 2007; Last Update: August 31, 2017.
• Emery-Dreifuss Muscular Dystrophy
  Rabah Ben Yaou, France Leturcq, and Gisèle Bonne.
  Initial Posting: September 29, 2004; Last Update: September 18, 2025.
• Encephalocraniocutaneous Lipomatosis
  Ute Moog and William B Dobyns.
  Initial Posting: January 27, 2022.
• Enlarged Parietal Foramina
  Lampros A Mavrogiannis and Andrew OM Wilkie.
  Initial Posting: March 30, 2004; Last Update: June 26, 2025.
• Epidermolysis Bullosa Simplex
  Jodi Y So and Joyce Teng.
  Initial Posting: October 7, 1998; Last Update: August 4, 2022.
• Epidermolysis Bullosa with Pyloric Atresia
  Anne W Lucky and Emily Gorell.
  Initial Posting: February 22, 2008; Last Update: January 26, 2023.
• Epimerase Deficiency Galactosemia
  Judith Fridovich-Keil, Lora Bean, Miao He, and Richard Schroer.
  Initial Posting: January 25, 2011; Last Update: March 4, 2021.
• Episodic Ataxia Type 1
  Sonia M Hasan and Maria Cristina D'Adamo.
  Initial Posting: February 9, 2010; Last Revision: November 1, 2018.
• Erythropoietic Protoporphyria, Autosomal Recessive
  Manisha Balwani, Joseph Bloomer, Robert Desnick; Porphyrias Consortium of the NIH-Sponsored Rare Diseases Clinical Research Network.
  Initial Posting: September 27, 2012; Last Update: September 7, 2017.
• Ethylmalonic Encephalopathy
  Ivano Di Meo, Costanza Lamperti, and Valeria Tiranti.
  Initial Posting: September 21, 2017.

• F

• FAM111A-Related Skeletal Dysplasias
  Shirley Cheng, Ivan FM Lo, and Ho-Ming Luk.
  Initial Posting: April 6, 2023.
• FARS2 Deficiency
  Mohammed Almannai, Eissa Faqeih, Ayman W El-Hattab, and Lee-Jun C Wong.
  Initial Posting: March 14, 2019.
• FBLN5-Related Cutis Laxa
  Lionel Van Maldergem and Bart Loeys.
  Initial Posting: March 19, 2009; Last Revision: June 15, 2023.
• FBN1-Related Marfan Syndrome
  Harry Dietz.
  Initial Posting: April 18, 2001; Last Update: February 17, 2022.
• FBXL4-Related Encephalomyopathic Mitochondrial DNA Depletion Syndrome
  Mohammed Almannai, Hongzheng Dai, Ayman W El-Hattab, and Lee-Jun C Wong.
  Initial Posting: April 6, 2017.
• FGFR Craniosynostosis Syndromes Overview
  Tara Wenger, Danny Miller, and Kelly Evans.
  Initial Posting: October 20, 1998; Last Revision: April 30, 2020.
• FGFR1-Related Hartsfield Syndrome
  Radhika Dhamija and Dusica Babovic-Vuksanovic.
  Initial Posting: March 3, 2016; Last Revision: May 12, 2022.
• FH Tumor Predisposition Syndrome
  Junne Kamihara, Kris Ann Schultz, and Huma Q Rana.
  Initial Posting: July 31, 2006; Last Update: May 8, 2025.
• FKBP14 Kyphoscoliotic Ehlers-Danlos Syndrome
  Cecilia Giunta, Marianne Rohrbach, Christine Fauth, and Matthias Baumann.
  Initial Posting: May 23, 2019.
• FLNA Deficiency
  Ming Hui Chen and Christopher A Walsh.
  Initial Posting: October 8, 2002; Last Update: September 30, 2021.
• FLNA-Related Otopalatodigital Spectrum Disorders
  Stephen Robertson and Emma Wade.
  Initial Posting: November 30, 2005; Last Update: June 26, 2025.
• FLNB-Related Disorders
  Stephen Robertson and Joanna Meira.
  Initial Posting: October 9, 2008; Last Update: September 11, 2025.
• FMR1 Disorders
  Jessica Ezzell Hunter, Elizabeth Berry-Kravis, Heather Hipp, and Peter K Todd.
  Initial Posting: June 16, 1998; Last Revision: May 16, 2024.
• FOLR1-Related Cerebral Folate Transport Deficiency
  I David Goldman.
  Initial Posting: January 11, 2024.
• FOXG1 Syndrome
  Knut Brockmann and Martin Staudt.
  Initial Posting: June 6, 2024; Last Revision: May 1, 2025.
• FOXP1 Syndrome
  Gudrun Rappold, Paige Siper, Ana Kostic, Ruth Braden, Angela Morgan, Saskia Koene, and Alexander Kolevzon.
  Initial Posting: September 21, 2023.
• FOXP2-Related Speech and Language Disorder
  Angela Morgan, Simon E Fisher, Ingrid Scheffer, and Michael Hildebrand.
  Initial Posting: June 23, 2016; Last Update: January 26, 2023.
• FREM1 Autosomal Recessive Disorders
  Chumei Li and Anne Slavotinek.
  Initial Posting: July 9, 2008; Last Update: May 1, 2025.
• FRMD7-Related Infantile Nystagmus
  Mervyn G Thomas, Gail Maconachie, Michael Hisaund, and Irene Gottlob.
  Initial Posting: February 12, 2009; Last Update: August 16, 2018.
• Fabry Disease
  Atul Mehta and Derralynn A Hughes.
  Initial Posting: August 5, 2002; Last Revision: April 11, 2024.
• Facioscapulohumeral Muscular Dystrophy
  Matthew K Preston and Leo H Wang.
  Initial Posting: March 8, 1999; Last Update: July 10, 2025.
• Factor V Leiden Thrombophilia
  Daniele Pastori, Danilo Menichelli, Emanuele Valeriani, and Pasquale Pignatelli.
  Initial Posting: May 14, 1999; Last Update: May 16, 2024.
• Familial Cerebral Cavernous Malformations
  Kelly D Flemming, Edward Smith, Douglas Marchuk, and W Brent Derry.
  Initial Posting: February 24, 2003; Last Update: July 27, 2023.
• Familial Combined Hypolipidemia
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: July 20, 2023.
• Familial Dysautonomia
  Bat-El Bar-Aluma.
  Initial Posting: January 21, 2003; Last Update: November 4, 2021.
• Familial Hemiplegic Migraine
  Joanna C Jen.
  Initial Posting: July 17, 2001; Last Revision: July 4, 2024.
• Familial Hemophagocytic Lymphohistiocytosis
  Kejian Zhang, Itziar Astigarraga, Yenan Bryceson, Kai Lehmberg, Rafal Machowicz, Rebecca Marsh, Elena Sieni, Zhao Wang, and Kim E Nichols.
  Initial Posting: March 22, 2006; Last Revision: June 6, 2024.
• Familial Hypercholesterolemia
  Hannah E Ison, Shoa L Clarke, and Joshua W Knowles.
  Initial Posting: January 2, 2014; Last Revision: January 30, 2025.
• Familial Lipoprotein Lipase Deficiency
  John R Burnett, Amanda J Hooper, and Robert A Hegele.
  Initial Posting: October 12, 1999; Last Update: June 22, 2017.
• Familial Mediterranean Fever
  Mordechai Shohat.
  Initial Posting: August 8, 2000; Last Update: December 15, 2016.
• Familial Paroxysmal Nonkinesigenic Dyskinesia
  Roberto Erro.
  Initial Posting: June 24, 2005; Last Update: April 4, 2019.
• Familial Porphyria Cutanea Tarda
  Sean Rudnick, John Phillips, Herbert Bonkovsky; Porphyrias Consortium of the Rare Diseases Clinical Research Network.
  Initial Posting: June 6, 2013; Last Update: June 9, 2022.
• Fanconi Anemia
  Parinda A Mehta and Christen Ebens.
  Initial Posting: February 14, 2002; Last Update: June 3, 2021.
• Fatty Acid Hydroxylase-Associated Neurodegeneration
  Allison Gregory, Sunita Venkateswaran, and Susan J Hayflick.
  Initial Posting: June 28, 2011; Last Update: September 27, 2018.
• Feingold Syndrome 1
  Carlo LM Marcelis and Arjan PM de Brouwer.
  Initial Posting: June 30, 2009; Last Update: April 4, 2019.
• Fibrous Dysplasia / McCune-Albright Syndrome
  Vivian Szymczuk, Pablo Florenzano, Luis F de Castro, Michael T Collins, and Alison M Boyce.
  Initial Posting: February 26, 2015; Last Update: February 8, 2024.
• Fibrodysplasia Ossificans Progressiva
  Lauren S Akesson and Ravi Savarirayan.
  Initial Posting: June 11, 2020; Last Revision: May 23, 2024.
• Free Sialic Acid Storage Disorder
  David Adams, Marjan Huizing, and Melissa Wasserstein.
  Initial Posting: June 13, 2003; Last Update: June 26, 2025.
• Friedreich Ataxia
  Sanjay I Bidichandani, Martin B Delatycki, Marek Napierala, and Antoine Duquette.
  Initial Posting: December 18, 1998; Last Revision: June 26, 2025.
• Fructose-1,6-Bisphosphatase Deficiency
  Sunita Bijarnia-Mahay, Sameer Bhatia, and Veronica Arora.
  Initial Posting: December 5, 2019.
• Fryns Syndrome
  Anne Slavotinek.
  Initial Posting: April 18, 2007; Last Update: September 17, 2020.
• Fukuyama Congenital Muscular Dystrophy
  Kayoko Saito.
  Initial Posting: January 26, 2006; Last Update: May 8, 2025.
• Fumarate Hydratase Deficiency
  David Coman, Kamil R Kranc, and John Christodoulou.
  Initial Posting: July 5, 2006; Last Update: April 23, 2020.

• G

• G6PC3 Deficiency
  Siddharth Banka.
  Initial Posting: April 16, 2015.
• GAN-Related Neurodegeneration
  Puneet Opal.
  Initial Posting: January 9, 2003; Last Update: October 14, 2021.
• GAA-FGF14-Related Ataxia
  David Pellerin, Matt Danzi, Mathilde Renaud, Henry Houlden, Matthis Synofzik, Stephan Zuchner, and Bernard Brais.
  Initial Posting: January 25, 2024.
• GARS1-Associated Axonal Neuropathy
  Rebecca Markovitz, Rajarshi Ghosh, Timothy Lotze, and Lorraine Potocki.
  Initial Posting: November 8, 2006; Last Update: July 22, 2021.
• GATA1-Related Cytopenia
  Kaoru Takasaki, Melissa A Kacena, Wendy H Raskind, Mitchell J Weiss, and Stella T Chou.
  Initial Posting: November 22, 2006; Last Update: February 16, 2023.
• GBE1 Adult Polyglucosan Body Disease
  H Orhan Akman, Alexander Lossos, and Or Kakhlon.
  Initial Posting: April 2, 2009; Last Update: September 17, 2020.
• GJB1 Disorders: Charcot-Marie-Tooth Neuropathy (CMT1X) and Central Nervous System Phenotypes
  Charles K Abrams.
  Initial Posting: June 18, 1998; Last Revision: April 25, 2024.
• GJB2-Related Autosomal Recessive Nonsyndromic Hearing Loss
  Richard JH Smith, Hela Azaiez, and Kevin Booth.
  Initial Posting: September 28, 1998; Last Update: July 20, 2023.
• GLB1-Related Disorders
  Debra S Regier, Cynthia J Tifft, and Caroline E Rothermel.
  Initial Posting: October 17, 2013; Last Update: April 22, 2021.
• GLI3-Related Greig Cephalopolysyndactyly Syndrome
  Leslie G Biesecker and Jennifer J Johnston.
  Initial Posting: July 9, 2001; Last Update: August 28, 2025.
• GLI3-Related Pallister-Hall Syndrome
  Leslie G Biesecker.
  Initial Posting: May 25, 2000; Last Revision: February 22, 2024.
• GM2 Activator Deficiency
  Changrui Xiao, Camilo Toro, and Cyndi Tifft.
  Initial Posting: August 25, 2022.
• GM3 Synthase Deficiency
  Vincent Cruz, Baozhong Xin, and Heng Wang.
  Initial Posting: July 20, 2023.
• GNAI1-Related Neurodevelopmental Disorder
  Emily Bonkowski, Esmat Fathi, and Heather C Mefford.
  Initial Posting: August 1, 2024.
• GNAO1-Related Disorder
  Lauren Briere, Moritz Thiel, David A Sweetser, Anne Koy, and Erika Axeen.
  Initial Posting: November 9, 2023.
• GNB1 Encephalopathy
  Anya Revah-Politi, Tristan T Sands, Sophie Colombo, David B Goldstein, and Kwame Anyane-Yeboa.
  Initial Posting: March 5, 2020; Last Revision: April 15, 2021.
• GNB5-Related Neurodevelopmental Disorder
  Gemma Poke, Lynette Grant Sadleir, Giuseppe Merla, Guillem de Valles-Ibáñez, and Jonathan Robert Skinner.
  Initial Posting: August 26, 2021; Last Revision: September 9, 2021.
• GNE Myopathy
  Nuria Carrillo, May Christine Malicdan, and Marjan Huizing.
  Initial Posting: March 26, 2004; Last Update: April 9, 2020.
• GNPTAB-Related Disorders
  Jules G Leroy, Sara S Cathey, and Michael J Friez.
  Initial Posting: August 26, 2008; Last Update: August 29, 2019.
• GRIA2-Related Neurodevelopmental Disorder
  Stephanie Efthymiou, Elisa Rumbos Siurana, Vincenzo Salpietro, Allan Bayat, and Henry Houlden.
  Initial Posting: January 11, 2024.
• GRIN1-Related Neurodevelopmental Disorder
  Konrad Platzer and Johannes R Lemke.
  Initial Posting: June 20, 2019; Last Revision: April 1, 2021.
• GRIN2A-Related Disorders
  Vincent Strehlow, Kenneth A Myers, Angela T Morgan, Ingrid E Scheffer, and Johannes R. Lemke.
  Initial Posting: September 29, 2016; Last Update: July 4, 2024.
• GRIN2B-Related Neurodevelopmental Disorder
  Konrad Platzer and Johannes R Lemke.
  Initial Posting: May 31, 2018; Last Revision: March 25, 2021.
• GRIN2D-Related Developmental and Epileptic Encephalopathy
  Konrad Platzer, Ilona Krey, and Johannes R Lemke.
  Initial Posting: July 28, 2022.
• GRN Frontotemporal Dementia
  Ging-Yuek Robin Hsiung and Howard H Feldman.
  Initial Posting: September 7, 2007; Last Update: February 6, 2020.
• GTP Cyclohydrolase 1-Deficient Dopa-Responsive Dystonia
  Yoshiaki Furukawa.
  Initial Posting: February 21, 2002; Last Update: January 24, 2019.
• Gabriele-de Vries Syndrome
  Maria J Nabais Sá, Michele Gabriele, Giuseppe Testa, and Bert BA de Vries.
  Initial Posting: May 30, 2019.
• Gaucher Disease
  Derralynn A Hughes and Gregory M Pastores.
  Initial Posting: July 27, 2000; Last Update: December 7, 2023.
• Geleophysic Dysplasia
  Pauline Marzin and Valérie Cormier-Daire.
  Initial Posting: September 22, 2009; Last Update: March 28, 2024.
• Generalized Arterial Calcification of Infancy
  Shira G Ziegler, William A Gahl, and Carlos R Ferreira.
  Initial Posting: November 13, 2014; Last Update: December 30, 2020.
• Genetic Atypical Hemolytic-Uremic Syndrome
  Marina Noris, Elena Bresin, Caterina Mele, and Giuseppe Remuzzi.
  Initial Posting: November 16, 2007; Last Update: September 23, 2021.
• Genetic Hearing Loss Overview
  A Eliot Shearer, Michael S Hildebrand, Amanda M Odell, and Richard JH Smith.
  Initial Posting: February 14, 1999; Last Revision: April 3, 2025.
• Genetic Prion Disease
  Inga Zerr and Matthias Schmitz.
  Initial Posting: March 27, 2003; Last Update: January 7, 2021.
• Genetic Steroid-Resistant Nephrotic Syndrome Overview
  Beata S Lipska-Ziętkiewicz.
  Initial Posting: August 26, 2021.
• Glucose Transporter Type 1 Deficiency Syndrome
  Dong Wang, Tristan Sands, Maoxue Tang, Umrao Monani, and Darryl De Vivo.
  Initial Posting: July 30, 2002; Last Update: March 6, 2025.
• Glutaric Acidemia Type 1
  Austin Larson and Steve Goodman.
  Initial Posting: September 19, 2019.
• Glycogen Storage Disease Type I
  Deeksha S Bali, Areeg El-Gharbawy, Stephanie Austin, Surekha Pendyal, and Priya S Kishnani.
  Initial Posting: April 19, 2006; Last Update: October 14, 2021.
• Glycogen Storage Disease Type III
  Andrea B Schreuder, Alessandro Rossi, Sarah C Grünert, and Terry GJ Derks.
  Initial Posting: March 9, 2010; Last Update: January 6, 2022.
• Glycogen Storage Disease Type IV
  Pilar L Magoulas and Ayman W El-Hattab.
  Initial Posting: January 3, 2013; Last Update: August 1, 2019.
• Glycogen Storage Disease Type V
  Miguel A Martín, Alejandro Lucia, Joaquin Arenas, and Antonio L Andreu.
  Initial Posting: April 19, 2006; Last Update: June 20, 2019.
• Glycogen Storage Disease Type VI
  Emma Labrador and David A Weinstein.
  Initial Posting: April 23, 2009; Last Update: November 27, 2019.

• H

• HEXA Disorders
  Camilo Toro, Leila Shirvan, and Cynthia Tifft.
  Initial Posting: March 11, 1999; Last Update: October 1, 2020.
• HFE-Related Hemochromatosis
  James C Barton and Charles J Parker.
  Initial Posting: April 3, 2000; Last Update: April 11, 2024.
• HIST1H1E Syndrome
  Deepika Burkardt and Katrina Tatton-Brown.
  Initial Posting: December 3, 2020; Last Revision: December 15, 2022.
• HNRNPH2-Related Neurodevelopmental Disorder
  Sehajvir Madhok and Jennifer Bain.
  Initial Posting: September 15, 2022.
• HNRNPU-Related Neurodevelopmental Disorder
  Meena Balasubramanian.
  Initial Posting: March 10, 2022.
• HOXA1-Related Disorders
  Prince Jacob, Venkatraman Bhat, and Siddaramappa J Patil.
  Initial Posting: November 14, 2024.
• HPRT1 Disorders
  Hyder A Jinnah.
  Initial Posting: September 25, 2000; Last Update: August 6, 2020.
• HRAS-Related Costello Syndrome
  Karen W Gripp and K Nicole Weaver.
  Initial Posting: August 29, 2006; Last Update: December 21, 2023.
• HTRA1 Disorder
  Osamu Onodera, Hiroaki Nozaki, and Toshio Fukutake.
  Initial Posting: April 27, 2010; Last Update: November 7, 2019.
• HYAL2 Deficiency
  James Fasham, Olivia K Wenger, Andrew H Crosby, and Emma L Baple.
  Initial Posting: September 21, 2023.
• Hand-Foot-Genital Syndrome
  Jeffrey W Innis.
  Initial Posting: July 11, 2006; Last Update: August 8, 2019.
• Haploinsufficiency of A20
  Natalie T Deuitch, Daniella M Schwartz, and Ivona Aksentijevich.
  Initial Posting: December 19, 2024.
• Hemophilia A
  Barbara A Konkle and Shelley Nakaya Fletcher.
  Initial Posting: September 21, 2000; Last Update: August 7, 2025.
• Hemophilia B
  Barbara A Konkle and Shelley Nakaya Fletcher.
  Initial Posting: October 2, 2000; Last Update: August 7, 2025.
• Hepatic Veno-Occlusive Disease with Immunodeficiency
  Melanie Wong.
  Initial Posting: February 21, 2007; Last Update: January 23, 2025.
• Hepatoerythropoietic Porphyria
  Sean Rudnick, John Phillips, Herbert Bonkovsky; Porphyrias Consortium of the Rare Diseases Clinical Research Network.
  Initial Posting: October 31, 2013; Last Update: December 22, 2022.
• Hereditary Ataxia Overview
  Susan Perlman.
  Initial Posting: October 28, 1998; Last Revision: February 20, 2025.
• Hereditary Coproporphyria
  Bruce Wang and D Montgomery Bissell.
  Initial Posting: December 13, 2012; Last Revision: May 19, 2022.
• Hereditary Distal Renal Tubular Acidosis
  R Todd Alexander, Helena Gil-Peña, Larry A Greenbaum, and Fernando Santos.
  Initial Posting: October 10, 2019; Last Update: April 3, 2025.
• Hereditary Dystonia Overview
  Christine Klein, Katja Lohmann, Connie Marras, and Alexander Münchau.
  Initial Posting: October 28, 2003; Last Update: June 22, 2017.
• Hereditary Fibrosing Poikiloderma with Tendon Contractures, Myopathy, and Pulmonary Fibrosis
  Sandra Mercier, Sébastien Küry, and Sébastien Barbarot.
  Initial Posting: October 13, 2016; Last Revision: September 9, 2021.
• Hereditary Folate Malabsorption
  I David Goldman.
  Initial Posting: June 17, 2008; Last Revision: February 15, 2024.
• Hereditary Fructose Intolerance
  Sommer Gaughan, Lachlan Ayres, and Peter R Baker, II.
  Initial Posting: December 17, 2015; Last Update: February 18, 2021.
• Hereditary Hemorrhagic Telangiectasia
  Jamie McDonald and David A Stevenson.
  Initial Posting: June 26, 2000; Last Update: November 24, 2021.
• Hereditary Hyperekplexia Overview
  Bettina Balint and Rhys Thomas.
  Initial Posting: July 31, 2007; Last Update: December 19, 2019.
• Hereditary Motor and Sensory Neuropathy with Agenesis of the Corpus Callosum
  Claudie Gauvreau, Jean-Denis Brisson, and Nicolas Dupré.
  Initial Posting: February 2, 2006; Last Update: September 17, 2020.
• Hereditary Multiple Osteochondromas
  Wim Wuyts, Gregory A Schmale, Howard A Chansky, and Wendy H Raskind.
  Initial Posting: August 3, 2000; Last Update: August 6, 2020.
• Hereditary Myopathy with Early Respiratory Failure
  Gerald Pfeffer and Patrick F Chinnery.
  Initial Posting: February 27, 2014; Last Revision: December 12, 2024.
• Hereditary Nephrogenic Diabetes Insipidus
  Nine Knoers and Henny Lemmink.
  Initial Posting: February 12, 2000; Last Update: February 27, 2020.
• Hereditary Neuropathy with Liability to Pressure Palsies
  Nicolas Chrestian.
  Initial Posting: September 28, 1998; Last Update: August 27, 2020.
• Hereditary Paraganglioma-Pheochromocytoma Syndromes
  Tobias Else, Samantha Greenberg, and Lauren Fishbein.
  Initial Posting: May 21, 2008; Last Update: September 21, 2023.
• Hereditary Sensory and Autonomic Neuropathy Type II
  Ingo Kurth.
  Initial Posting: November 23, 2010; Last Update: April 1, 2021.
• Hereditary Transthyretin Amyloidosis
  Yoshiki Sekijima and Katsuya Nakamura.
  Initial Posting: November 5, 2001; Last Update: May 30, 2024.
• Heritable Pulmonary Arterial Hypertension Overview
  Eric D Austin, John A Phillips, III, and James E Loyd.
  Initial Posting: July 18, 2002; Last Update: December 23, 2020.
• Heritable Thoracic Aortic Disease Overview
  Dianna M Milewicz and Alana C Cecchi.
  Initial Posting: February 13, 2003; Last Update: May 4, 2023.
• Hermansky-Pudlak Syndrome
  Wendy J Introne, Marjan Huizing, May Christine V Malicdan, Kevin J O'Brien, and William A Gahl.
  Initial Posting: July 24, 2000; Last Revision: May 25, 2023.
• Hidrotic Ectodermal Dysplasia 2
  Jemima Mellerio and Danielle Greenblatt.
  Initial Posting: April 25, 2005; Last Revision: April 3, 2025.
• Holoprosencephaly Overview
  Cedrik Tekendo-Ngongang, Maximilian Muenke, and Paul Kruszka.
  Initial Posting: December 27, 2000; Last Update: March 5, 2020.
• Holt-Oram Syndrome
  Clémence Vanlerberghe and Florence Petit.
  Initial Posting: July 20, 2004; Last Update: July 31, 2025.
• Homocystinuria due to Cystathionine Beta-Synthase Deficiency
  Stephanie J Sacharow and Harvey L Levy.
  Initial Posting: January 15, 2004; Last Update: September 25, 2025.
• Homocystinuria due to Deficiency of N(5,10)-Methylenetetrahydrofolate Reductase Activity
  Muhammad Umair and Majid Alfadhel.
  Initial Posting: May 29, 2025; Last Revision: July 10, 2025.
• Huntington Disease
  Nicholas S Caron, Galen EB Wright, and Michael R Hayden.
  Initial Posting: October 23, 1998; Last Update: June 11, 2020.
• Huntington Disease-Like 2
  David G Anderson, Amanda Krause, and Russell L Margolis.
  Initial Posting: January 30, 2004; Last Update: April 10, 2025.
• Huppke-Brendel Syndrome
  Bindu Parayil Sankaran, Shwetha Chiplunkar, VP Vandana, Madhu Nagappa, Periyasamy Govindaraj, and AB Taly.
  Initial Posting: June 13, 2019; Last Update: April 3, 2025.
• Hutchinson-Gilford Progeria Syndrome
  Leslie B Gordon, W Ted Brown, and Francis S Collins.
  Initial Posting: December 12, 2003; Last Update: March 13, 2025.
• Hyaline Fibromatosis Syndrome
  Joseph TC Shieh, H Eugene Hoyme, and Laura T Arbour.
  Initial Posting: February 27, 2008; Last Revision: May 11, 2023.
• Hyperkalemic Periodic Paralysis
  Frank Weber.
  Initial Posting: July 18, 2003; Last Update: July 1, 2021.
• Hypermanganesemia with Dystonia 1
  Karin Tuschl, Peter T Clayton, Sidney M Gospe, Jr, and Philippa B Mills.
  Initial Posting: August 30, 2012; Last Update: December 23, 2021.
• Hypermobile Ehlers-Danlos Syndrome
  Alan Hakim.
  Initial Posting: October 22, 2004; Last Update: February 22, 2024.
• Hyperornithinemia-Hyperammonemia-Homocitrullinuria Syndrome
  Jose Camacho and Natalia Rioseco-Camacho.
  Initial Posting: May 31, 2012; Last Revision: April 10, 2025.
• Hyperphosphatemic Familial Tumoral Calcinosis
  Mary Scott Ramnitz, Rachel I Gafni, and Michael T Collins.
  Initial Posting: February 1, 2018.
• Hypochondroplasia
  Michael B Bober, Gary A Bellus, Moira S Cheung, Mahim Jain, Sarah M Nikkel, and George E Tiller.
  Initial Posting: July 15, 1999; Last Update: September 25, 2025.
• Hypohidrotic Ectodermal Dysplasia
  J Timothy Wright, Dorothy K Grange, and Mary Fete.
  Initial Posting: April 28, 2003; Last Revision: March 20, 2025.
• Hypokalemic Periodic Paralysis
  Frank Weber and Frank Lehmann-Horn.
  Initial Posting: April 30, 2002; Last Update: July 26, 2018.
• Hypomyelination and Congenital Cataract
  Nicole I Wolf, Roberta Biancheri, Federico Zara, Claudio Bruno, Elisabetta Gazzerro, Andrea Rossi, Marjo S van der Knaap, and Carlo Minetti.
  Initial Posting: October 14, 2008; Last Update: January 14, 2021.
• Hypophosphatasia
  Kathryn M Dahir and Mark E Nunes.
  Initial Posting: November 20, 2007; Last Update: March 27, 2025.

• I

• IDEDNIK Syndrome
  Hessa S Alsaif and Fowzan S Alkuraya.
  Initial Posting: November 14, 2024.
• IMAGe Syndrome
  Samantha A Schrier Vergano and Matthew A Deardorff.
  Initial Posting: March 13, 2014; Last Update: August 5, 2021.
• INPPL1-Related Opsismodysplasia
  Samuel Huang, Dawn Earl, and Klane White.
  Initial Posting: June 12, 2025.
• INSR-Related Severe Insulin Resistance Syndrome
  Aviv Mesika, Aharon Klar, and Tzipora C Falik Zaccai.
  Initial Posting: January 25, 2018; Last Update: April 25, 2024.
• IPEX Syndrome
  Queenie K-G Tan, Raymond J Louie, and John W Sleasman.
  Initial Posting: October 19, 2004; Last Update: February 1, 2024.
• IRF2BPL-Related Disorder
  Tomas Vanagunas, Elizabeth Ulm Seiwert, Travis R Larsh, Paul C Marcogliese, and Loren DM Pena.
  Initial Posting: November 21, 2024.
• IRF6-Related Disorders
  Brian C Schutte, Howard M Saal, Steven Goudy, and Elizabeth J Leslie.
  Initial Posting: October 30, 2003; Last Update: March 4, 2021.
• ISCA1-Related Multiple Mitochondrial Dysfunctions Syndrome
  Anju Shukla, Dhanya Lakshmi Narayanan, Parneet Kaur, and Katta Mohan Girisha.
  Initial Posting: October 3, 2019.
• ISCA2-Related Mitochondrial Disorder
  Zuhair N Al-Hassnan and Namik Kaya.
  Initial Posting: February 22, 2018.
• Inclusion Body Myopathy with Paget Disease of Bone and/or Frontotemporal Dementia
  Virginia Kimonis.
  Initial Posting: May 25, 2007; Last Update: September 12, 2019.
• Incontinentia Pigmenti
  Angela E Scheuerle and Matilde Valeria Ursini.
  Initial Posting: June 8, 1999; Last Revision: April 3, 2025.
• Isolated and Classic Cutis Marmorata Telangiectatica Congenita
  Joan Tamburro, Elias I Traboulsi, and Millan S Patel.
  Initial Posting: June 9, 2022.
• Isolated Gonadotropin-Releasing Hormone (GnRH) Deficiency
  Ravikumar Balasubramanian and William F Crowley, Jr.
  Initial Posting: May 23, 2007; Last Revision: May 12, 2022.
• Isolated Methylmalonic Acidemia
  Irini Manoli, Jennifer L Sloan, and Charles P Venditti.
  Initial Posting: August 16, 2005; Last Update: September 8, 2022.
• Isolated Sulfite Oxidase Deficiency
  Parayil Sankaran Bindu, Madhu Nagappa, Rose Dawn Bharath, and Arun B Taly.
  Initial Posting: September 21, 2017.

• J

• Jervell and Lange-Nielsen Syndrome
  Lisbeth Tranebjærg, Ricardo A Samson, and Glenn Edward Green.
  Initial Posting: July 29, 2002; Last Update: August 17, 2017.
• Joubert Syndrome
  Ian A Glass, Jennifer C Dempsey, Melissa Parisi, and Dan Doherty.
  Initial Posting: July 9, 2003; Last Update: March 13, 2025.
• Junctional Epidermolysis Bullosa
  Ellen G Pfendner and Anne W Lucky.
  Initial Posting: February 22, 2008; Last Update: December 20, 2018.
• Juvenile Hemochromatosis
  Alberto Piperno, Francesca Bertola, and Angela Bentivegna.
  Initial Posting: February 17, 2005; Last Update: January 9, 2020.
• Juvenile Polyposis Syndrome
  Joy Larsen Haidle, Suzanne P MacFarland, and James R Howe.
  Initial Posting: May 13, 2003; Last Update: February 3, 2022.

• K

• KAT6B Disorders
  Gabrielle Lemire, Philippe M Campeau, and Brendan H Lee.
  Initial Posting: December 13, 2012; Last Update: January 2, 2020.
• KBG Syndrome
  Dayna Morel Swols and Mustafa Tekin.
  Initial Posting: March 22, 2018.
• KCNK9 Imprinting Syndrome
  Neda Zadeh and John M Graham, Jr.
  Initial Posting: March 23, 2017.
• KCNQ2-Related Disorders
  Francesco Miceli, Maria Virginia Soldovieri, Sarah Weckhuysen, Edward Cooper, and Maurizio Taglialatela.
  Initial Posting: April 27, 2010; Last Update: May 19, 2022.
• KCNQ3-Related Disorders
  Francesco Miceli, Maria Virginia Soldovieri, Sarah Weckhuysen, Edward C Cooper, and Maurizio Taglialatela.
  Initial Posting: May 22, 2014; Last Update: September 28, 2023.
• KCNT1-Related Epilepsy
  Tracy Gertler, David Bearden, Arin Bhattacharjee, and Gemma Carvill.
  Initial Posting: September 20, 2018.
• KCTD7-Related Progressive Myoclonic Epilepsy
  Sangeetha Yoganathan, Puneet Jain, Gregory Costain, and Robyn Whitney.
  Initial Posting: November 20, 2025.
• KMT2B-Related Disorders
  Lucia Abela and Manju Ann Kurian.
  Initial Posting: April 26, 2018; Last Update: May 22, 2025.
• KMT2E-Related Neurodevelopmental Disorder
  Lynn Pais, Lance Rodan, and Anne O'Donnell-Luria.
  Initial Posting: April 18, 2024.
• KPTN-Related Disorder
  Lettie E Rawlins, Peter B Crino, Philip H Iffland, Andrew H Crosby, and Emma L Baple.
  Initial Posting: August 1, 2024.
• Kabuki Syndrome
  Margaret P Adam and Mark Hannibal.
  Initial Posting: September 1, 2011; Last Revision: August 14, 2025.
• Kagami-Ogata Syndrome
  Tsutomu Ogata and Masayo Kagami.
  Initial Posting: October 24, 2024.
• Kaufman Oculocerebrofacial Syndrome
  Dana Brabbing-Goldstein and Lina Basel-Salmon.
  Initial Posting: October 20, 2016; Last Update: July 28, 2022.
• Kindler Syndrome
  Leila Youssefian, Hassan Vahidnezhad, and Jouni Uitto.
  Initial Posting: March 3, 2016; Last Update: January 6, 2022.
• Kleefstra Syndrome
  Tjitske Kleefstra and Nicole de Leeuw.
  Initial Posting: October 5, 2010; Last Revision: January 26, 2023.
• Koolen-de Vries Syndrome
  David A Koolen, Angela Morgan, and Bert BA de Vries.
  Initial Posting: January 26, 2010; Last Update: February 2, 2023.
• Krabbe Disease
  Joseph J Orsini, Maria L Escolar, Melissa P Wasserstein, and Michele Caggana.
  Initial Posting: June 19, 2000; Last Update: October 11, 2018.

• L

• L1 Syndrome
  Connie Stumpel and Yvonne J Vos.
  Initial Posting: April 28, 2004; Last Update: January 7, 2021.
• LAMA2 Muscular Dystrophy
  Jorge Oliveira, João Parente Freixo, Manuela Santos, and Teresa Coelho.
  Initial Posting: June 7, 2012; Last Update: September 17, 2020.
• LMNA-Related Dilated Cardiomyopathy
  Ray E Hershberger and Elizabeth Jordan.
  Initial Posting: June 12, 2008; Last Update: March 17, 2022.
• LMNB1-Related Autosomal Dominant Leukodystrophy
  Raili Raininko, Michael Gosky, and Quasar S Padiath.
  Initial Posting: January 7, 2016; Last Update: July 15, 2021.
• LPIN2-Related Majeed Syndrome
  Dhanya Lakshmi Narayanan, Kishore Sai Gogineni, and Vaishnavi Ashok Badiger.
  Initial Posting: March 2, 2023.
• LRRK2 Parkinson Disease
  Rachel Saunders-Pullman, Deborah Raymond, and Sonya Elango.
  Initial Posting: November 2, 2006; Last Revision: July 6, 2023.
• LTBP4-Related Cutis Laxa
  Bert L Callewaert and Zsolt Urban.
  Initial Posting: February 11, 2016; Last Revision: February 23, 2023.
• LZTR1- andSMARCB1-Related Schwannomatosis
  Radhika Dhamija, Scott Plotkin, Alicia Gomes, and Dusica Babovic-Vuksanovic.
  Initial Posting: March 8, 2018; Last Revision: April 25, 2024.
• Laing Distal Myopathy
  Phillipa Lamont and Nigel G Laing.
  Initial Posting: October 17, 2006; Last Update: February 4, 2021.
• Lathosterolosis
  Pankaj Prasun and Jaya Ganesh.
  Initial Posting: December 7, 2023.
• Leber Congenital Amaurosis / Early-Onset Severe Retinal Dystrophy Overview
  Neruban Kumaran, Mark E Pennesi, Paul Yang, Karmen M Trzupek, Catherine Schlechter, Anthony T Moore, Richard G Weleber, and Michel Michaelides.
  Initial Posting: October 4, 2018; Last Revision: March 23, 2023.
• Leber Hereditary Optic Neuropathy
  Patrick Yu-Wai-Man and Patrick F Chinnery.
  Initial Posting: October 26, 2000; Last Update: March 11, 2021.
• Legius Syndrome
  Eric Legius and David Stevenson.
  Initial Posting: October 14, 2010; Last Update: August 6, 2020.
• Leukoencephalopathy with Brain Stem and Spinal Cord Involvement and Lactate Elevation
  Marc Engelen, Truus EM Abbink, Gajja S Salomons, and Marjo S van der Knaap.
  Initial Posting: May 25, 2010; Last Update: February 18, 2021.
• Li-Fraumeni Syndrome
  Katherine Schneider, Kristin Zelley, Kim E Nichols, Alison Schwartz Levine, and Judy Garber.
  Initial Posting: January 19, 1999; Last Revision: May 1, 2025.
• Lipoid Proteinosis
  Hassan Vahidnezhad, Leila Youssefian, and Jouni Uitto.
  Initial Posting: January 21, 2016; Last Update: July 22, 2021.
• Loeys-Dietz Syndrome
  Bart L Loeys and Harry C Dietz.
  Initial Posting: February 28, 2008; Last Update: September 12, 2024.
• Long QT Syndrome Overview
  Alexander J Groffen, Hennie Bikker, and Imke Christiaans.
  Initial Posting: February 20, 2003; Last Update: March 21, 2024.
• Long-Chain Hydroxyacyl-CoA Dehydrogenase Deficiency / Trifunctional Protein Deficiency
  Pankaj Prasun, Mary Kate LoPiccolo, and Ilona Ginevic.
  Initial Posting: September 1, 2022.
• Lowe Syndrome
  Richard Alan Lewis, Robert L Nussbaum, and Eileen D Brewer.
  Initial Posting: July 24, 2001; Last Update: April 18, 2019.
• Lymphedema-Distichiasis Syndrome
  Sahar Mansour, Glen W Brice, Steve Jeffery, and Peter Mortimer.
  Initial Posting: March 29, 2005; Last Update: April 4, 2019.
• Lynch Syndrome
  Gregory Idos and Laura Valle.
  Initial Posting: February 5, 2004; Last Update: February 4, 2021.
• Lysinuric Protein Intolerance
  Virginia Nunes and Harri Niinikoski.
  Initial Posting: December 21, 2006; Last Update: April 12, 2018.
• Lysosomal Acid Lipase Deficiency
  Erin P Hoffman, Marci L Barr, Monica A Giovanni, and Michael F Murray.
  Initial Posting: July 30, 2015; Last Revision: September 1, 2016.

• M

• MAPT-Related Frontotemporal Dementia
  Jonathan Rohrer, Brigid Ryan, and Rebekah Ahmed.
  Initial Posting: November 7, 2000; Last Update: August 18, 2022.
• MBD5 Haploinsufficiency
  Sureni V Mullegama, Roberto Mendoza-Londono, and Sarah H Elsea.
  Initial Posting: October 27, 2016; Last Update: April 28, 2022.
• MBTPS1-Related Spondyloepimetaphyseal Dysplasia with Elevated Lysosomal Enzymes
  Hua Wang, Andrea Wierenga, Sandeep Prabhu, and Klaas Wierenga.
  Initial Posting: November 30, 2023.
• MECP2 Disorders
  Simranpreet Kaur and John Christodoulou.
  Initial Posting: October 3, 2001; Last Update: September 19, 2019.
• MECP2 Duplication Syndrome
  Hilde Van Esch.
  Initial Posting: January 18, 2008; Last Update: May 21, 2020.
• MECR-Related Neurologic Disorder
  Gali Heimer, Allison Gregory, Penelope Hogarth, Susan Hayflick, and Bruria Ben Zeev.
  Initial Posting: May 9, 2019.
• MED12-Related Disorders
  Michael J Lyons.
  Initial Posting: June 23, 2008; Last Update: August 12, 2021.
• MED13L Syndrome
  Alicia Nicole Campbell, Jennifer Bain, and Steven James Doyle.
  Initial Posting: April 10, 2025.
• MEF2C-Related Disorder
  Jessica Cooley Coleman and Steven A Skinner.
  Initial Posting: December 12, 2024.
• MELAS
  Ayman W El-Hattab, Mohammed Almannai, and Fernando Scaglia.
  Initial Posting: February 27, 2001; Last Update: November 29, 2018.
• MERRF
  Frances Velez-Bartolomei, Chung Lee, and Gregory Enns.
  Initial Posting: June 3, 2003; Last Update: January 7, 2021.
• MFN2 Hereditary Motor and Sensory Neuropathy
  Stephan Züchner.
  Initial Posting: February 18, 2005; Last Revision: March 27, 2025.
• MID1-Related Opitz G/BBB Syndrome
  Germana Meroni.
  Initial Posting: December 17, 2004; Last Update: October 19, 2023.
• MIRAGE Syndrome
  Kanako Tanase-Nakao, Timothy S Olson, and Satoshi Narumi.
  Initial Posting: November 25, 2020.
• MN1 C-Terminal Truncation Syndrome
  Christopher CY Mak, Jasmine LF Fung, Mianne Lee, Angela E Lin, Jeanne Amiel, Dan Doherty, Christopher T Gordon, and Brian HY Chung.
  Initial Posting: August 13, 2020.
• MPPH Syndrome
  Ghayda Mirzaa.
  Initial Posting: November 17, 2016; Last Update: July 28, 2022.
• MPV17-Related Mitochondrial DNA Maintenance Defect
  Ayman W El-Hattab, Julia Wang, Hongzheng Dai, Mohammed Almannai, Fernando Scaglia, William J Craigen, and Lee-Jun C Wong.
  Initial Posting: May 17, 2012; Last Update: May 17, 2018.
• MUTYH Polyposis
  Maartje Nielsen, Elena Infante, and Randall Brand.
  Initial Posting: October 4, 2012; Last Revision: May 27, 2021.
• MYH9-Related Disease
  Anna Savoia and Alessandro Pecci.
  Initial Posting: November 20, 2008; Last Update: February 18, 2021.
• MYRF-Related Cardiac Urogenital Syndrome
  Julie D Kaplan, Blythe Stewart, Lev Prasov, and Tucker Louise C Pyle.
  Initial Posting: November 10, 2022; Last Update: July 31, 2025.
• Mandibulofacial Dysostosis with Microcephaly
  Matthew Lines, Taila Hartley, Stella K MacDonald, and Kym M Boycott.
  Initial Posting: July 3, 2014; Last Revision: April 6, 2023.
• Maple Syrup Urine Disease
  Kevin A Strauss, Erik G Puffenberger, and Vincent J Carson.
  Initial Posting: January 30, 2006; Last Update: April 23, 2020.
• Marinesco-Sjögren Syndrome
  Anna-Kaisa Anttonen.
  Initial Posting: November 29, 2006; Last Update: October 3, 2024.
• Maternal 15q Duplication Syndrome
  Laina Lusk, Vanessa Vogel-Farley, Charlotte DiStefano, and Shafali Jeste.
  Initial Posting: June 16, 2016; Last Update: July 15, 2021.
• Maternal Effect Gene-Related Multilocus Imprinting Disturbances
  Zeynep Tümer, Thomas Eggermann, Saskia Maas, Jet Bliek, and Deborah Mackay.
  Initial Posting: May 15, 2025; Last Revision: August 28, 2025.
• Maturity-Onset Diabetes of the Young Overview
  Rochelle Naylor, Amy Knight Johnson, and Daniela del Gaudio.
  Initial Posting: May 24, 2018.
• McKusick-Kaufman Syndrome
  Anne M Slavotinek.
  Initial Posting: September 10, 2002; Last Update: December 3, 2020.
• McLeod Neuroacanthocytosis Syndrome
  Hans H Jung, Adrian Danek, Ruth H Walker, Beat M Frey, and Kevin Peikert.
  Initial Posting: December 3, 2004; Last Update: September 16, 2021.
• Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency
  Irene J Chang, Christina Lam, and Jerry Vockley.
  Initial Posting: April 20, 2000; Last Update: September 26, 2024.
• Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome Overview
  Lusine Ambartsumyan.
  Initial Posting: May 9, 2019; Last Update: August 1, 2024.
• Megalencephalic Leukoencephalopathy with Subcortical Cysts
  Rogier Min, Truus EM Abbink, and Marjo S van der Knaap.
  Initial Posting: August 11, 2003; Last Update: July 27, 2023.
• Microcephalic Osteodysplastic Primordial Dwarfism Type II
  Angela Duker, Andrew Jackson, and Michael B Bober.
  Initial Posting: December 30, 2021; Last Revision: November 20, 2025.
• Microcephaly-Capillary Malformation Syndrome
  Melissa T Carter, Ghayda Mirzaa, Laura M McDonell, and Kym M Boycott.
  Initial Posting: December 12, 2013; Last Update: March 18, 2021.
• Microphthalmia with Linear Skin Defects Syndrome
  Manuela Morleo and Brunella Franco.
  Initial Posting: June 18, 2009; Last Update: July 26, 2018.
• Milroy Disease
  Malou Van Zanten, Sahar Mansour, Pia Ostergaard, Peter Mortimer, and Kristiana Gordon.
  Initial Posting: April 27, 2006; Last Update: February 18, 2021.
• Mitochondrial DNA-Associated Leigh Syndrome Spectrum
  Megan Ball, David R Thorburn, and Shamima Rahman.
  Initial Posting: October 30, 2003; Last Update: May 9, 2024.
• Mitochondrial DNA Maintenance Defects Overview
  Ayman W El-Hattab, William J Craigen, Lee-Jun C Wong, and Fernando Scaglia.
  Initial Posting: March 8, 2018.
• Mitochondrial Membrane Protein-Associated Neurodegeneration
  Allison Gregory, Thomas Klopstock, Tomasz Kmiec, Penelope Hogarth, and Susan J Hayflick.
  Initial Posting: February 27, 2014; Last Update: March 4, 2021.
• Mitochondrial Neurogastrointestinal Encephalopathy Disease
  Michio Hirano.
  Initial Posting: April 22, 2005; Last Update: January 14, 2016.
• Mitochondrial Short-Chain Enoyl-CoA Hydratase 1 Deficiency
  Rebecca Ganetzky and Carol Stojinski.
  Initial Posting: June 20, 2019.
• Molybdenum Cofactor Deficiency
  Albert Misko, Karishma Mahtani, Jessica Abbott, Guenter Schwarz, and Paldeep Atwal.
  Initial Posting: December 2, 2021; Last Revision: February 2, 2023.
• Monogenic Parkinson Disease Overview
  Huw Morris and Shen-Yang Lim.
  Initial Posting: May 25, 2004; Last Update: May 15, 2025.
• Monosomy 7 Predisposition Syndromes Overview
  Timothy S Olson, Kathryn E Dickerson, Taizo A Nakano, and Marcin Wlodarski.
  Initial Posting: June 10, 2021.
• Mucolipidosis III Gamma
  Annick Raas-Rothschild and Ronen Spiegel.
  Initial Posting: January 28, 2010; Last Update: November 21, 2019.
• Mucolipidosis IV
  Albert Misko, Yulia Grishchuk, Ehud Goldin, and Raphael Schiffmann.
  Initial Posting: January 28, 2005; Last Update: February 11, 2021.
• Mucopolysaccharidosis Type I
  Lorne A Clarke.
  Initial Posting: October 31, 2002; Last Revision: April 11, 2024.
• Mucopolysaccharidosis Type II
  Maurizio Scarpa and Christina Lampe.
  Initial Posting: November 6, 2007; Last Update: January 16, 2025.
• Mucopolysaccharidosis Type III
  Victoria F Wagner and Hope Northrup.
  Initial Posting: September 19, 2019.
• Mucopolysaccharidosis Type IVA
  Debra S Regier, Matthew Oetgen, and Pranoot Tanpaiboon.
  Initial Posting: July 11, 2013; Last Update: June 17, 2021.
• Mucopolysaccharidosis Type VII
  Angela Sun and Raymond Wang.
  Initial Posting: January 4, 2024.
• Muenke Syndrome
  Paul Kruszka, Myron Rolle, Kristopher T Kahle, and Maximilian Muenke.
  Initial Posting: May 10, 2006; Last Update: March 30, 2023.
• Multicentric Osteolysis Nodulosis and Arthropathy
  Gandham SriLakshmi Bhavani, Hitesh Shah, Anju Shukla, and Katta Mohan Girisha.
  Initial Posting: July 14, 2016; Last Revision: March 30, 2023.
• Multiple Acyl-CoA Dehydrogenase Deficiency
  Pankaj Prasun.
  Initial Posting: June 18, 2020.
• Multiple Endocrine Neoplasia Type 1
  Francesca Giusti, Francesca Marini, and Maria Luisa Brandi.
  Initial Posting: August 31, 2005; Last Update: March 10, 2022.
• Multiple Endocrine Neoplasia Type 2
  Charis Eng and Gilman Plitt.
  Initial Posting: September 27, 1999; Last Update: August 10, 2023.
• Multiple Endocrine Neoplasia Type 4
  Pamela Brock and Lawrence Kirschner.
  Initial Posting: September 21, 2023.
• Multiple Epiphyseal Dysplasia, Autosomal Dominant
  Michael D Briggs, Michael J Wright, and Geert R Mortier.
  Initial Posting: January 8, 2003; Last Update: July 4, 2024.
• Multiple Sulfatase Deficiency
  Lars Schlotawa, Laura Adang, Mauricio De Castro, and Rebecca Ahrens-Nicklas.
  Initial Posting: March 21, 2019.
• Musculocontractural Ehlers-Danlos Syndrome
  Tomoki Kosho, Tomomi Yamaguchi, Shuji Mizumoto, and Roberto Mendoza-Londono.
  Initial Posting: May 15, 2025.
• Myhre Syndrome
  Angela E Lin, Nicola Brunetti-Pierri, Mark E Lindsay, Lisa A Schimmenti, and Lois J Starr.
  Initial Posting: April 13, 2017; Last Update: December 12, 2024.
• Myotonia Congenita
  Morten Dunø and John Vissing.
  Initial Posting: August 3, 2005; Last Update: February 25, 2021.
• Myotonic Dystrophy Type 1
  Thomas D Bird.
  Initial Posting: September 17, 1999; Last Revision: November 14, 2024.
• Myotonic Dystrophy Type 2
  Felix Kleefeld, Hannes Erdmann, and Benedikt Schoser.
  Initial Posting: September 21, 2006; Last Update: September 25, 2025.

• N

• NARS1-Related Neurologic Disorders
  Stephanie Efthymiou, Sara Nagy, Busra Aynekin, and Henry Houlden.
  Initial Posting: February 27, 2025.
• NDP-Related Retinopathies
  Brittni A Scruggs, Madeline Q Reding, and Lisa A Schimmenti.
  Initial Posting: July 30, 1999; Last Revision: March 23, 2023.
• NF2-Related Schwannomatosis
  D Gareth Evans.
  Initial Posting: October 14, 1998; Last Update: April 20, 2023.
• NFIA-Related Disorder
  T Niroshini Senaratne and Fabiola Quintero-Rivera.
  Initial Posting: June 13, 2019.
• NFIX-Related Malan Syndrome
  Manuela Priolo.
  Initial Posting: August 1, 2024.
• NGLY1-Related Congenital Disorder of Deglycosylation
  Christina Lam, Lynne Wolfe, Anna Need, Vandana Shashi, and Gregory Enns.
  Initial Posting: February 8, 2018.
• NKX2-1-Related Disorders
  Neepa Jayant Patel and Joseph Jankovic.
  Initial Posting: February 20, 2014; Last Update: June 29, 2023.
• NKX6-2-Related Disorder
  Viorica Chelban, Namik Kaya, Fowzan Alkuraya, and Henry Houlden.
  Initial Posting: October 4, 2018.
• NOTCH3-Related Lateral Meningocele Syndrome
  Resham Ejaz, Melissa Carter, and Karen Gripp.
  Initial Posting: June 23, 2016; Last Update: May 5, 2022.
• NR0B1-Related Adrenal Hypoplasia Congenita
  John C Achermann and Eric J Vilain.
  Initial Posting: November 20, 2001; Last Update: January 25, 2018.
• NR2F1-Related Neurodevelopmental Disorder
  Christian P Schaaf, Patrick Yu-Wai-Man, and Ilia Valentin.
  Initial Posting: December 8, 2022.
• NSDHL-Related Disorders
  Mazen Kurban, Jinia El Feghaly, and Lamiaa Hamie.
  Initial Posting: February 1, 2011; Last Update: September 5, 2024.
• NTHL1 Tumor Syndrome
  Richarda M De Voer, Maartje Nielsen, Weilun Gao, Roland P Kuiper, and Nicoline Hoogerbrugge.
  Initial Posting: April 2, 2020; Last Update: March 20, 2025.
• NTRK1 Congenital Insensitivity to Pain with Anhidrosis
  Yasuhiro Indo.
  Initial Posting: August 5, 2008; Last Update: April 30, 2020.
• Nail-Patella Syndrome
  Elizabeth Sweeney, Julie E Hoover-Fong, and Iain McIntosh.
  Initial Posting: May 31, 2003; Last Revision: December 14, 2023.
• Nephronophthisis-Related Ciliopathies
  Marijn Stokman, Marc Lilien, and Nine Knoers.
  Initial Posting: June 23, 2016; Last Update: March 2, 2023.
• Neurodegeneration with Brain Iron Accumulation Disorders Overview
  Allison Gregory, Manju A Kurian, Jenny Wilson, and Susan Hayflick.
  Initial Posting: February 28, 2013; Last Update: March 6, 2025.
• Neuroferritinopathy
  Patrick F Chinnery.
  Initial Posting: April 25, 2005; Last Update: October 20, 2022.
• Neurofibromatosis 1
  Jan M Friedman.
  Initial Posting: October 2, 1998; Last Revision: April 3, 2025.
• Neuronal Ceroid Lipofuscinoses Overview
  Kristina Malik, Kourtney Santucci, Leighann Sremba, Maija Steenari, Andrea Miele, Scott Demarest, and Ineka Whiteman.
  Initial Posting: October 10, 2001; Last Update: May 29, 2025.
• Nevoid Basal Cell Carcinoma Syndrome
  D Gareth Evans.
  Initial Posting: June 20, 2002; Last Update: February 22, 2024.
• Niemann-Pick Disease Type C
  Tatiana Bremova-Ertl and Marc Patterson.
  Initial Posting: January 26, 2000; Last Update: November 20, 2025.
• Nijmegen Breakage Syndrome
  Raymonda Varon, Ilja Demuth, and Krystyna H Chrzanowska.
  Initial Posting: May 17, 1999; Last Revision: November 30, 2023.
• Nonketotic Hyperglycinemia
  Johan LK Van Hove, Curtis Coughlin, II, Michael Swanson, and Julia B Hennermann.
  Initial Posting: November 14, 2002; Last Update: May 23, 2019.
• Nonsyndromic 46,XX Testicular Disorders/Differences of Sex Development
  Emmanuèle C Délot and Eric J Vilain.
  Initial Posting: October 30, 2003; Last Update: May 26, 2022.
• Nonsyndromic Disorders of Testicular Development Overview
  Lauren Mohnach, Patricia Y Fechner, and Catherine E Keegan.
  Initial Posting: May 21, 2008; Last Update: August 18, 2022.
• Nonsyndromic Genetic Hyperinsulinism Overview
  David Gillis.
  Initial Posting: August 19, 2003; Last Update: October 31, 2024.
• Nonsyndromic Hearing Loss and Deafness, Mitochondrial
  Shin-ichi Usami and Shin-ya Nishio.
  Initial Posting: October 22, 2004; Last Update: June 14, 2018.
• Nonsyndromic Hypertrophic Cardiomyopathy Overview
  Allison L Cirino, Nadine Channaoui, and Carolyn Ho.
  Initial Posting: August 5, 2008; Last Update: March 6, 2025.
• Nonsyndromic Malignant Hyperthermia Susceptibility
  Sheila Riazi, Leslie G Biesecker, Henry Rosenberg, and Robert T Dirksen.
  Initial Posting: December 19, 2003; Last Update: August 7, 2025.
• Nonsyndromic Retinitis Pigmentosa Overview
  Abigail T Fahim, Stephen P Daiger, and Richard G Weleber.
  Initial Posting: August 4, 2000; Last Revision: April 6, 2023.
• Nonsyndromic Tooth Agenesis Overview
  Ariadne Letra, Brett Chiquet, Emily Hansen-Kiss, Simone Menezes, and Elizabeth Hunter.
  Initial Posting: July 22, 2021.
• Noonan Syndrome
  Amy E Roberts.
  Initial Posting: November 15, 2001; Last Revision: June 5, 2025.
• Noonan Syndrome with Multiple Lentigines
  Bruce D Gelb and Marco Tartaglia.
  Initial Posting: November 30, 2007; Last Update: June 30, 2022.
• Nuclear Gene-Encoded Leigh Syndrome Spectrum Overview
  Shamima Rahman, David R Thorburn, and Megan Ball.
  Initial Posting: October 1, 2015; Last Update: May 1, 2025.

• O

• OTOF-Related Hearing Loss
  Hela Azaiez, Ryan K Thorpe, Amanda M Odell, and Richard JH Smith.
  Initial Posting: February 29, 2008; Last Update: March 13, 2025.
• Oculocutaneous Albinism and Ocular Albinism Overview
  Mervyn G Thomas, Jonathan Zippin, and Brian P Brooks.
  Initial Posting: April 13, 2023.
• Oculocutaneous Albinism Type 4
  Masahiro Hayashi and Tamio Suzuki.
  Initial Posting: November 17, 2005; Last Update: September 7, 2017.
• Oculopharyngeal Muscular Dystrophy
  Capucine Trollet, Alexis Boulinguiez, Fanny Roth, Tanya Stojkovic, Gillian Butler-Browne, Teresinha Evangelista, Jean Lacau St Guily, and Pascale Richard.
  Initial Posting: March 8, 2001; Last Update: October 22, 2020.
• Okur-Chung Neurodevelopmental Syndrome
  Wendy Chung and Volkan Okur.
  Initial Posting: June 9, 2022.
• Oral-Facial-Digital Syndrome Type I
  Brunella Franco, Ange-Line Bruel, and Christel Thauvin-Robinet.
  Initial Posting: July 24, 2002; Last Update: May 11, 2023.
• Ornithine Transcarbamylase Deficiency
  Uta Lichter-Konecki, Ljubica Caldovic, Hiroki Morizono, Kara Simpson, Nicholas Ah Mew, and Erin MacLeod.
  Initial Posting: August 29, 2013; Last Revision: May 26, 2022.
• Osteoglophonic Dysplasia
  Amna A Othman, Holly E Babcock, and Carlos R Ferreira.
  Initial Posting: April 18, 2024.
• Osteopathia Striata with Cranial Sclerosis
  Russell Gear and Ravi Savarirayan.
  Initial Posting: April 15, 2021; Last Revision: March 30, 2023.

• P

• PACS1 Neurodevelopmental Disorder
  Laina Lusk, Simone Smith, Christa Martin, Cora Taylor, and Wendy Chung.
  Initial Posting: July 16, 2020.
• PAFAH1B1-Related Lissencephaly / Subcortical Band Heterotopia
  Stefanie Brock, William B Dobyns, and Anna Jansen.
  Initial Posting: March 3, 2009; Last Update: March 25, 2021.
• PAX2-Related Disorder
  Matthew A Bower, Lisa A Schimmenti, and Michael R Eccles.
  Initial Posting: June 8, 2007; Last Revision: August 14, 2025.
• PAX6-Related Aniridia
  Mariya Moosajee, Melanie Hingorani, and Anthony T Moore.
  Initial Posting: May 20, 2003; Last Update: October 18, 2018.
• PEX7-Related Rhizomelic Chondrodysplasia Punctata
  Nancy E Braverman, Ricki Carroll, Candace Muss, Wedad Fallatah, and Mahim Jain.
  Initial Posting: November 16, 2001; Last Update: August 7, 2025.
• PI4KA-Related Disorder
  Emma L Baple, Claire Salter, Holm Uhlig, Nicole I Wolf, and Andrew H Crosby.
  Initial Posting: August 11, 2022.
• PIK3CA-Related Overgrowth Spectrum
  Ghayda Mirzaa, John M Graham, Jr, and Kim Keppler-Noreuil.
  Initial Posting: August 15, 2013; Last Revision: April 6, 2023.
• PINK1 Type of Young-Onset Parkinson Disease
  Lara M Lange and Christine Klein.
  Initial Posting: March 16, 2010; Last Update: April 25, 2024.
• PLA2G6-Associated Neurodegeneration
  Allison Gregory, Manju A Kurian, Eamonn R Maher, Penelope Hogarth, and Susan J Hayflick.
  Initial Posting: June 19, 2008; Last Update: March 23, 2017.
• PLOD1-Related Kyphoscoliotic Ehlers-Danlos Syndrome
  Marianne Rohrbach and Cecilia Giunta.
  Initial Posting: February 2, 2000; Last Update: June 13, 2024.
• PLP1-Related Disorders
  Nicole I Wolf, Rosalina ML van Spaendonk, and Grace M Hobson.
  Initial Posting: June 15, 1999; Last Update: June 12, 2025.
• PLPBP Deficiency
  Hilal Al-Shekaili, Jolita Ciapaite, Clara van Karnebeek, and Izabella Pena.
  Initial Posting: February 16, 2023.
• PMM2-CDG
  Christina Lam and Donna M Krasnewich.
  Initial Posting: August 15, 2005; Last Update: May 20, 2021.
• PNPLA6 Disorders
  Matthis Synofzik, Robert B Hufnagel, and Stephan Züchner.
  Initial Posting: October 9, 2014; Last Update: June 10, 2021.
• PNPO Deficiency
  Barbara Plecko and Philippa Mills.
  Initial Posting: June 23, 2022.
• POLG-Related Disorders
  Bruce H Cohen, Patrick F Chinnery, and William C Copeland.
  Initial Posting: March 16, 2010; Last Update: February 29, 2024.
• POLR3-Related Leukodystrophy
  Geneviève Bernard and Adeline Vanderver.
  Initial Posting: August 2, 2012; Last Update: May 11, 2017.
• PORCN-Related Developmental Disorders
  V Reid Sutton.
  Initial Posting: May 15, 2008; Last Update: June 15, 2023.
• POT1 Tumor Predisposition
  Marie-Louise Accardo, Jenae Osborne, and Tobias Else.
  Initial Posting: October 29, 2020; Last Update: February 13, 2025.
• PPP1R12A-Related Urogenital and/or Brain Malformation Syndrome
  Ebba Alkhunaizi and David Chitayat.
  Initial Posting: September 9, 2021; Last Revision: March 7, 2024.
• PPP2R1A-Related Neurodevelopmental Disorder
  Sofia Douzgou, Veerle Janssens, and Gunnar Houge.
  Initial Posting: May 12, 2022.
• PPP2R5D-Related Neurodevelopmental Disorder
  Ghayda Mirzaa, Kimberly Foss, Khemika Sudnawa, and Wendy K Chung.
  Initial Posting: January 24, 2019; Last Update: January 9, 2025.
• PRICKLE1-Related Disorders
  Mario Mastrangelo, Caterina Caputi, Dario Esposito, and Vincenzo Leuzzi.
  Initial Posting: September 8, 2009; Last Update: April 21, 2022.
• PROP1-Related Combined Pituitary Hormone Deficiency
  Luciani Renata Carvalho, Mirian Yumie Nishi, Fernanda Azevedo Correa, Juliana Moreira Marques, Ivo Jorge Prado Arnhold, and Berenice B Mendonca.
  Initial Posting: December 7, 2000; Last Update: February 24, 2022.
• PRRT2-Related Disorder
  Kathryn Yang, Vincente Quiroz, and Darius Ebrahimi-Fakhari.
  Initial Posting: January 11, 2018; Last Update: July 4, 2024.
• PRSS1-Related Hereditary Pancreatitis
  David C Whitcomb.
  Initial Posting: March 1, 2012; Last Update: March 27, 2025.
• PTEN Hamartoma Tumor Syndrome
  Lamis Yehia and Charis Eng.
  Initial Posting: November 29, 2001; Last Revision: August 7, 2025.
• PTH1R-Related Jansen Metaphyseal Chondrodysplasia
  Fiona Obiezu, Alison Boyce, Harald Jüppner, and Smita Jha.
  Initial Posting: July 10, 2025.
• PTS-Related Tetrahydrobiopterin Deficiency (PTPSD)
  Thomas Opladen, Nicola Longo, and Nenad Blau.
  Initial Posting: July 10, 2025.
• PURA-Related Neurodevelopmental Disorders
  Margot RF Reijnders, Richard J Leventer, Bo Hoon Lee, Diana Baralle, Paulo Selber, Alex R Paciorkowski, and David Hunt.
  Initial Posting: April 27, 2017.
• Pachyonychia Congenita
  Frances JD Smith, C David Hansen, Peter R Hull, Roger L Kaspar, WH Irwin McLean, Edel O’Toole, and Eli Sprecher.
  Initial Posting: January 27, 2006; Last Update: November 30, 2017.
• Pancreatitis Overview
  Celeste Shelton, Jessica LaRusch, and David C Whitcomb.
  Initial Posting: March 13, 2014; Last Update: July 2, 2020.
• Pantothenate Kinase-Associated Neurodegeneration
  Allison Gregory and Susan J Hayflick.
  Initial Posting: August 13, 2002; Last Update: August 3, 2017.
• Parkin Type of Early-Onset Parkinson Disease
  Norbert Brüggemann and Christine Klein.
  Initial Posting: April 17, 2001; Last Update: April 23, 2020.
• Pediatric Genetic Cholestatic Liver Disease Overview
  Maria Amendola and James E Squires.
  Initial Posting: September 15, 2022; Last Revision: May 25, 2023.
• Pelizaeus-Merzbacher-Like Disease 1
  Norah Nahhas, Alex Conant, Jennifer Orthmann-Murphy, Adeline Vanderver, and Grace Hobson.
  Initial Posting: December 21, 2017; Last Revision: January 17, 2019.
• Periodontal Ehlers-Danlos Syndrome
  Ines Kapferer-Seebacher, Fleur S van Dijk, and Johannes Zschocke.
  Initial Posting: July 29, 2021.
• Permanent Neonatal Diabetes Mellitus
  Diva D De León and Sara E Pinney.
  Initial Posting: February 8, 2008; Last Revision: September 18, 2025.
• Perrault Syndrome Overview
  Tianyi Li, Rabia Faridi, William G Newman, and Thomas B Friedman.
  Initial Posting: September 25, 2014; Last Update: May 8, 2025.
• Peters Plus Syndrome
  Saskia AJ Lesnik Oberstein, Claudia AL Ruivenkamp, and Raoul C Hennekam.
  Initial Posting: October 8, 2007; Last Revision: January 30, 2025.
• Peutz-Jeghers Syndrome
  Thomas J McGarrity, Christopher I Amos, and Maria J Baker.
  Initial Posting: February 23, 2001; Last Update: September 2, 2021.
• Phelan-McDermid Syndrome-SHANK3 Related
  Katy Phelan, R Curtis Rogers, and Luigi Boccuto.
  Initial Posting: May 11, 2005; Last Update: June 6, 2024.
• Phenylalanine Hydroxylase Deficiency
  Georgianne Arnold and Jerry Vockley.
  Initial Posting: January 10, 2000; Last Revision: November 20, 2025.
• Phosphoribosylpyrophosphate Synthetase Superactivity
  Arjan PM de Brouwer and John Christodoulou.
  Initial Posting: September 23, 2008; Last Update: February 17, 2022.
• Phosphoribosylpyrophosphate Synthetase Deficiency
  Arjan PM de Brouwer and John Christodoulou.
  Initial Posting: October 21, 2008; Last Update: June 8, 2023.
• Phosphorylase Kinase Deficiency
  Mrudu Herbert, Jennifer L Goldstein, Catherine Rehder, Stephanie Austin, Priya S Kishnani, and Deeksha S Bali.
  Initial Posting: May 31, 2011; Last Update: November 1, 2018.
• Pitt-Hopkins Syndrome
  David A Sweetser, Kevin S Gipson, and Claire Zar-Kessler.
  Initial Posting: August 30, 2012; Last Update: May 22, 2025.
• Poikiloderma with Neutropenia
  Lisa Wang, Carol Clericuzio, Lidia Larizza, and Daniela Concolino.
  Initial Posting: October 26, 2017; Last Update: February 22, 2024.
• Polycystic Kidney Disease, Autosomal Dominant
  Peter C Harris and Vicente E Torres.
  Initial Posting: January 10, 2002; Last Update: September 29, 2022.
• Polycystic Lipomembranous Osteodysplasia with Sclerosing Leukoencephalopathy
  Juha Paloneva, Taina Autti, Panu Hakola, and Matti J Haltia.
  Initial Posting: January 24, 2002; Last Update: December 10, 2020.
• Pompe Disease
  Ethan Sperry, Nancy Leslie, Lisa Berry, and Loren Pena.
  Initial Posting: August 31, 2007; Last Update: August 21, 2025.
• Potocki-Lupski Syndrome
  Lorraine Potocki, Juanita Neira-Fresneda, and Bo Yuan.
  Initial Posting: August 24, 2017.
• Prader-Willi Syndrome
  Daniel J Driscoll, Jennifer L Miller, and Suzanne B Cassidy.
  Initial Posting: October 6, 1998; Last Revision: December 5, 2024.
• Primary Carnitine Deficiency
  Ayman W El-Hattab and Mohammed Almannai.
  Initial Posting: March 15, 2012; Last Update: December 5, 2024.
• Primary Ciliary Dyskinesia
  Maimoona A Zariwala, Katherine A Despotes, and Stephanie D Davis.
  Initial Posting: January 24, 2007; Last Update: May 22, 2025.
• Primary Congenital Glaucoma
  Khaled K Abu-Amero and Deepak P Edward.
  Initial Posting: September 30, 2004; Last Update: August 17, 2017.
• Primary Coenzyme Q₁₀ Deficiency Overview
  Leonardo Salviati, Eva Trevisson, Caterina Agosto, Mara Doimo, and Placido Navas.
  Initial Posting: January 26, 2017; Last Update: June 8, 2023.
• Primary Familial Brain Calcification Overview
  Alexander Balck, Christine Klein, and Ana Westenberger.
  Initial Posting: April 18, 2004; Last Update: September 18, 2025.
• Primary Familial and Congenital Erythrocytosis
  Josef Prchal.
  Initial Posting: November 10, 2016; Last Update: January 23, 2025.
• Primary Hyperoxaluria Type 1
  Dawn S Milliner, Peter C Harris, David J Sas, Andrea G Cogal, and John C Lieske.
  Initial Posting: June 19, 2002; Last Update: August 15, 2024.
• Primary Hyperoxaluria Type 2
  Gill Rumsby and Sally-Anne Hulton.
  Initial Posting: December 2, 2008; Last Update: December 21, 2017.
• Primary Hyperoxaluria Type 3
  Dawn S Milliner, Peter C Harris, David J Sas, and John C Lieske.
  Initial Posting: September 24, 2015; Last Update: February 9, 2023.
• Primary Mitochondrial Disorders Overview
  Patrick F Chinnery.
  Initial Posting: June 8, 2000; Last Update: July 29, 2021.
• Primary Pyruvate Dehydrogenase Complex Deficiency Overview
  Rebecca Ganetzky, Elizabeth M McCormick, and Marni J Falk.
  Initial Posting: June 17, 2021.
• Primary Trimethylaminuria
  Ian R Phillips and Elizabeth A Shephard.
  Initial Posting: October 8, 2007; Last Update: November 5, 2020.
• Primrose Syndrome
  Veronica Arora, Carlos R Ferreira, Ratna Dua Puri, and Ishwar Chandar Verma.
  Initial Posting: May 6, 2021; Last Revision: June 17, 2021.
• Progressive Myoclonic Epilepsy Type 1
  Anna-Elina Lehesjoki and Reetta Kälviäinen.
  Initial Posting: June 24, 2004; Last Update: July 2, 2020.
• Progressive Myoclonus Epilepsy, Lafora Type
  Berge Minassian.
  Initial Posting: December 28, 2007; Last Update: January 23, 2025.
• Progressive Pseudorheumatoid Dysplasia
  Gandham SriLakshmi Bhavani, Hitesh Shah, Anju Shukla, Ashwin Dalal, and Katta Mohan Girisha.
  Initial Posting: November 25, 2015; Last Update: December 23, 2020.
• Prolidase Deficiency
  Francis Rossignol, Heng Wang, and Carlos Ferreira.
  Initial Posting: June 25, 2015; Last Update: July 7, 2022.
• Propionic Acidemia
  Carolina I Galarreta Aima, Oleg A Shchelochkov, Teodoro Jerves Serrano, and Charles P Venditti.
  Initial Posting: May 17, 2012; Last Update: September 26, 2024.
• Proteus Syndrome
  Leslie G Biesecker and Julie C Sapp.
  Initial Posting: August 9, 2012; Last Update: May 25, 2023.
• Prothrombin Thrombophilia
  Jody L Kujovich.
  Initial Posting: July 25, 2006; Last Update: February 4, 2021.
• Pseudohypoaldosteronism Type II
  David H Ellison.
  Initial Posting: November 10, 2011; Last Update: February 16, 2017.
• Pseudoxanthoma Elasticum
  Sharon F Terry and Jouni Uitto.
  Initial Posting: June 5, 2001; Last Update: June 4, 2020.
• Pulmonary Fibrosis Predisposition Overview
  Christine Kim Garcia and Janet L Talbert.
  Initial Posting: January 21, 2005; Last Revision: May 12, 2022.
• Pycnodysostosis
  Shannon LeBlanc and Ravi Savarirayan.
  Initial Posting: November 5, 2020; Last Revision: April 6, 2023.
• Pyridoxine-Dependent Epilepsy –ALDH7A1
  Sidney M Gospe, Jr.
  Initial Posting: December 7, 2001; Last Update: September 22, 2022.
• Pyruvate Carboxylase Deficiency
  Maria Laura Duque Lasio, April N Lehman, Ayesha Ahmad, and Jirair K Bedoyan.
  Initial Posting: June 2, 2009; Last Update: May 30, 2024.

• R

• RAB18 Deficiency
  Mark Handley and Eamonn Sheridan.
  Initial Posting: January 4, 2018.
• RERE-Related Disorders
  Daryl A Scott and Elliott H Sherr.
  Initial Posting: March 21, 2019.
• RFC1 CANVAS / Spectrum Disorder
  Andrea Cortese, Mary M Reilly, and Henry Houlden.
  Initial Posting: November 25, 2020.
• RNU4atac-opathy
  Angela Duker, Danita Velasco, Nic Robertson, Andrew Jackson, Magee DeFelice, and Michael B Bober.
  Initial Posting: February 16, 2023.
• ROR2-Related Robinow Syndrome
  Carlos A Bacino.
  Initial Posting: July 28, 2005; Last Revision: September 12, 2019.
• RPE65-Related Leber Congenital Amaurosis / Early-Onset Severe Retinal Dystrophy
  Daniel L Chao, Amanda Burr, and Mark Pennesi.
  Initial Posting: November 14, 2019.
• RPS6KA3-Related Intellectual Disability
  R Curtis Rogers and Fatima E Abidi.
  Initial Posting: July 16, 2002; Last Update: March 16, 2023.
• RRM2B Mitochondrial DNA Maintenance Defects
  Albert Z Lim, Robert McFarland, Robert W Taylor, and Gráinne S Gorman.
  Initial Posting: April 17, 2014; Last Update: June 24, 2021.
• RUNX1 Familial Platelet Disorder with Associated Myeloid Malignancies
  Natalie Deuitch, Elizabeth Broadbridge, Lea Cunningham, and Paul Liu.
  Initial Posting: March 4, 2021; Last Revision: January 11, 2024.
• Retinal Vasculopathy with Cerebral Leukoencephalopathy and Systemic Manifestations
  Irene de Boer, Nadine Pelzer, and Gisela Terwindt.
  Initial Posting: September 19, 2019.
• Retinoblastoma
  Dietmar R Lohmann and Brenda L Gallie.
  Initial Posting: July 18, 2000; Last Update: September 21, 2023.
• Rhabdoid Tumor Predisposition Syndrome
  Karolina Nemes, Susanne Bens, Franck Bourdeaut, Pascal Johann, Uwe Kordes, Reiner Siebert, and Michael C Frühwald.
  Initial Posting: December 7, 2017; Last Update: May 12, 2022.
• Riboflavin Transporter Deficiency
  Elisa Cali, Natalia Dominik, Andreea Manole, and Henry Houlden.
  Initial Posting: June 11, 2015; Last Update: April 8, 2021.
• Ritscher-Schinzel Syndrome
  Alison M Elliott and Albert Chudley.
  Initial Posting: January 23, 2020.
• Rothmund-Thomson Syndrome
  Lisa L Wang and Sharon E Plon.
  Initial Posting: October 6, 1999; Last Revision: June 4, 2020.
• Rotor Syndrome
  Milan Jirsa, AS Knisely, Alfred Schinkel, and Stanislav Kmoch.
  Initial Posting: December 13, 2012; Last Update: February 27, 2025.
• Rubinstein-Taybi Syndrome
  Cathy A Stevens.
  Initial Posting: August 30, 2002; Last Update: November 9, 2023.

• S

• SALL1-Related Townes-Brocks Syndrome
  Claudio Graziano and Giulia Olivucci.
  Initial Posting: January 24, 2007; Last Revision: August 14, 2025.
• SALL4-Related Disorders
  Jürgen Kohlhase.
  Initial Posting: August 16, 2004; Last Update: March 17, 2022.
• SAMD9L Ataxia-Pancytopenia Syndrome
  Wendy H Raskind, Dong-Hui Chen, and Thomas Bird.
  Initial Posting: June 1, 2017; Last Update: February 4, 2021.
• SATB2-Associated Syndrome
  Yuri A Zarate, Katherine Bosanko, and Jennifer Fish.
  Initial Posting: October 12, 2017; Last Update: June 20, 2024.
• SCARB2-Related Action Myoclonus – Renal Failure Syndrome
  Changrui Xiao, Haejun Ahn, Sara Kibrom, and Camilo Toro.
  Initial Posting: December 17, 2015; Last Update: February 9, 2023.
• SCN1A Seizure Disorders
  Ian O Miller and Marcio A Sotero de Menezes.
  Initial Posting: November 29, 2007; Last Revision: February 17, 2022.
• SCN3A-Related Neurodevelopmental Disorder
  Katherine L Helbig and Ethan M Goldberg.
  Initial Posting: June 3, 2021; Last Revision: May 1, 2025.
• SCN8A-Related Epilepsy and/or Neurodevelopmental Disorders
  Michael F Hammer, Maya Xia, and John M Schreiber.
  Initial Posting: August 25, 2016; Last Update: April 6, 2023.
• SCN9A Neuropathic Pain Syndromes
  Fuki M Hisama, Sulayman D Dib-Hajj, and Stephen G Waxman.
  Initial Posting: May 6, 2006; Last Update: January 23, 2020.
• SERAC1 Deficiency
  Saskia B Wortmann, Arjan PM de Brouwer, Ron A Wevers, and Eva Morava.
  Initial Posting: April 17, 2014; Last Update: July 23, 2020.
• SETBP1 Haploinsufficiency Disorder
  Angela Morgan, Siddharth Srivastava, Jessica Duis, and Bregje van Bon.
  Initial Posting: November 18, 2021; Last Revision: May 9, 2024.
• SETD1B-Related Neurodevelopmental Disorder
  Alexandra Roston and William Gibson.
  Initial Posting: September 29, 2022; Last Revision: February 27, 2025.
• SETD2 Neurodevelopmental Disorders
  John Pappas and Rachel Rabin.
  Initial Posting: December 30, 2021; Last Revision: September 22, 2022.
• SGCE Myoclonus-Dystonia
  Deborah Raymond, Rachel Saunders-Pullman, and Laurie Ozelius.
  Initial Posting: May 21, 2003; Last Revision: June 4, 2020.
• SH3TC2-Related Hereditary Motor and Sensory Neuropathy
  Hamid Azzedine and Mustafa A Salih.
  Initial Posting: March 31, 2008; Last Update: March 11, 2021.
• SHORT Syndrome
  A Micheil Innes and David A Dyment.
  Initial Posting: May 15, 2014; Last Update: June 4, 2020.
• SHOX Deficiency Disorders
  Gerhard Binder and Gudrun A Rappold.
  Initial Posting: December 12, 2005; Last Revision: May 23, 2024.
• SLC12A5-Related Epilepsy of Infancy with Migrating Focal Seizures
  Amy McTague and Manju A Kurian.
  Initial Posting: February 14, 2019.
• SLC19A1-Related Folate Transport Deficiency
  I David Goldman.
  Initial Posting: August 14, 2025.
• SLC25A19-Related Thiamine Metabolism Dysfunction
  Brahim Tabarki, Farah Thabet, and Majid Alfadhel.
  Initial Posting: September 4, 2003; Last Update: March 30, 2023.
• SLC25A24 Fontaine Progeroid Syndrome
  Danita Velasco, Ann Haskins Olney, and Lois Starr.
  Initial Posting: June 9, 2022.
• SLC26A2-Related Atelosteogenesis
  Andrea Superti-Furga and Sheila Unger.
  Initial Posting: August 30, 2002; Last Revision: March 16, 2023.
• SLC26A2-Related Multiple Epiphyseal Dysplasia
  Sheila Unger and Andrea Superti-Furga.
  Initial Posting: August 29, 2002; Last Update: January 19, 2023.
• SLC26A4-Related Sensorineural Hearing Loss
  Richard JH Smith, Hela Azaiez, and Amanda M Odell.
  Initial Posting: September 28, 1998; Last Revision: April 3, 2025.
• SMARCA2-Related Nicolaides-Baraitser Syndrome
  Omar Abdul-Rahman and Francis May.
  Initial Posting: October 15, 2015; Last Update: March 6, 2025.
• SLC39A8-CDG
  Julien H Park.
  Initial Posting: April 6, 2023.
• SLC39A14 Deficiency
  Karin Tuschl, Allison Gregory, Esther Meyer, Peter T Clayton, Susan J Hayflick, Philippa B Mills, and Manju A Kurian.
  Initial Posting: May 25, 2017; Last Update: December 8, 2022.
• SLC6A1-Related Neurodevelopmental Disorder
  Kimberly Goodspeed, Scott Demarest, Katrine Johannesen, Jingqiong Kang, Dennis Lal, and Katie Angione.
  Initial Posting: February 9, 2023.
• SLC6A3-Related Dopamine Transporter Deficiency Syndrome
  Robert VV Spaull and Manju A Kurian.
  Initial Posting: July 27, 2017; Last Update: September 28, 2023.
• SOST-Related Sclerosing Bone Dysplasias
  Natasha Appelman-Dijkstra, Antoon Van Lierop, and Socrates Papapoulos.
  Initial Posting: June 4, 2002; Last Update: August 1, 2024.
• SOX2 Disorder
  Kathleen A Williamson, T Michael Yates, and David R FitzPatrick.
  Initial Posting: February 23, 2006; Last Update: July 30, 2020.
• SPTBN4 Disorder
  Xilma Ortiz-Gonzalez and Klaas Wierenga.
  Initial Posting: July 16, 2020.
• SPTLC1-Related Hereditary Sensory Neuropathy
  Garth A Nicholson.
  Initial Posting: September 23, 2002; Last Revision: December 2, 2021.
• SRCAP-Related Floating-Harbor Syndrome
  Malgorzata JM Nowaczyk, Sarah M Nikkel, and Susan M White.
  Initial Posting: November 29, 2012; Last Update: April 10, 2025.
• STAC3 Disorder
  Bryn D Webb, Irini Manoli, and Ethylin Wang Jabs.
  Initial Posting: June 20, 2019.
• STAT3 Hyper IgE Syndrome
  Amy P Hsu, Joie Davis, Jennifer M Puck, Steven M Holland, and Alexandra F Freeman.
  Initial Posting: February 23, 2010; Last Update: March 26, 2020.
• STRC-Related Autosomal Recessive Hearing Loss
  Shelby Redfield and A Eliot Shearer.
  Initial Posting: December 14, 2023.
• STXBP1 Encephalopathy with Epilepsy
  Saadet Mercimek-Andrews.
  Initial Posting: December 1, 2016; Last Update: September 28, 2023.
• SUCLA2-Related Mitochondrial DNA Depletion Syndrome, Encephalomyopathic Form with Methylmalonic Aciduria
  Ayman W El-Hattab and Fernando Scaglia.
  Initial Posting: May 26, 2009; Last Update: September 28, 2023.
• SUCLG1-Related Mitochondrial DNA Depletion Syndrome, Encephalomyopathic Form with Methylmalonic Aciduria
  Ayman W El-Hattab and Fernando Scaglia.
  Initial Posting: March 30, 2017.
• SYNE1 Deficiency
  Marie Beaudin, Pierre-Luc Gamache, François Gros-Louis, and Nicolas Dupré.
  Initial Posting: February 23, 2007; Last Update: December 6, 2018.
• SYNGAP1-Related Intellectual Disability
  J Lloyd Holder, Jr, Fadi F Hamdan, and Jacques L Michaud.
  Initial Posting: February 21, 2019; Last Revision: August 14, 2025.
• Saethre-Chotzen Syndrome
  Emily R Gallagher, Chootima Ratisoontorn, and Michael L Cunningham.
  Initial Posting: May 16, 2003; Last Update: January 24, 2019.
• Salih Myopathy
  Peter Hackman, Marco Savarese, Maria Francesca Di Feo, Bjarne Udd, and Mustafa A Salih.
  Initial Posting: January 12, 2012; Last Update: April 3, 2025.
• Sandhoff Disease
  Changrui Xiao, Cynthia Tifft, and Camilo Toro.
  Initial Posting: April 14, 2022.
• Saul-Wilson Syndrome
  Carlos Ferreira.
  Initial Posting: February 20, 2020.
• Schaaf-Yang Syndrome
  Christian P Schaaf and Felix Marbach.
  Initial Posting: February 11, 2021; Last Revision: November 4, 2021.
• Schimke Immunoosseous Dysplasia
  Elizabeth Lippner, Thomas Lücke, Carlos Salgado, Cornelius Boerkoel, and David B Lewis.
  Initial Posting: October 1, 2002; Last Revision: March 30, 2023.
• Schinzel-Giedion Syndrome
  Jessica Duis and Bregje WM van Bon.
  Initial Posting: March 7, 2024.
• Schmid Metaphyseal Chondrodysplasia
  Christopher Mark Richmond and Ravi Savarirayan.
  Initial Posting: October 21, 2019; Last Update: May 9, 2024.
• Sepiapterin Reductase Deficiency
  Jennifer Friedman and Serena Galosi.
  Initial Posting: July 1, 2015; Last Update: September 18, 2025.
• Serine Deficiency Disorders
  Saskia N van der Crabben and Tom J de Koning.
  Initial Posting: June 22, 2023.
• Shashi-Pena Syndrome
  Julie M Porter, Loren DM Pena, Rebecca C Spillmann, Amanda Johnson, and Vandana Shashi.
  Initial Posting: November 7, 2024.
• Short-Chain Acyl-CoA Dehydrogenase Deficiency
  Lynne Wolfe, Reena Jethva, Devin Oglesbee, and Jerry Vockley.
  Initial Posting: September 22, 2011; Last Update: September 11, 2025.
• Shprintzen-Goldberg Syndrome
  Marie T Greally.
  Initial Posting: January 13, 2006; Last Update: April 9, 2020.
• Shwachman-Diamond Syndrome
  Adam Nelson and Kasiani Myers.
  Initial Posting: July 17, 2008; Last Update: September 19, 2024.
• Sickle Cell Disease
  MA Bender and Katie Carlberg.
  Initial Posting: September 15, 2003; Last Revision: February 13, 2025.
• Silver-Russell Syndrome
  Howard M Saal, Madeleine D Harbison, and Irene Netchine.
  Initial Posting: November 2, 2002; Last Revision: January 9, 2025.
• Simpson-Golabi-Behmel Syndrome Type 1
  Alex F Nisbet, Evan R Hathaway, and Jennifer M Kalish.
  Initial Posting: December 19, 2006; Last Revision: November 14, 2024.
• Single Large-Scale Mitochondrial DNA Deletion Syndromes
  Amy Goldstein and Marni J Falk.
  Initial Posting: December 17, 2003; Last Update: September 28, 2023.
• Sitosterolemia
  Semone B Myrie, Robert D Steiner, and David Mymin.
  Initial Posting: April 4, 2013; Last Update: July 16, 2020.
• Smith-Kingsmore Syndrome
  Carlos E Prada, Carolyn R Raski, Ghayda Mirzaa, Aaron Besterman, Darcy A Krueger, and Andrew C Liu.
  Initial Posting: November 20, 2025.
• Smith-Lemli-Opitz Syndrome
  Malgorzata JM Nowaczyk and Christopher A Wassif.
  Initial Posting: November 13, 1998; Last Update: January 30, 2020.
• Smith-Magenis Syndrome
  Ann CM Smith, John Berens, Kerry E Boyd, Christine Brennan, Andrea Gropman, Barbara Haas-Givler, Christopher Vlangos, Rebecca Foster, Rachel Franciskovich, Santhosh Girirajan, Nancy Raitano Lee, Cora Taylor, Sinan Omer Turnacioglu, and Sarah H Elsea.
  Initial Posting: October 22, 2001; Last Update: May 29, 2025.
• Snyder-Robinson Syndrome
  Charles E Schwartz, Caleb Bupp, Mary Jo Kutler, and Angela Peron.
  Initial Posting: June 27, 2013; Last Update: August 7, 2025.
• Sotos Syndrome
  Sharon Ocansey, Trevor RP Cole, Nazneen Rahman, and Katrina Tatton-Brown.
  Initial Posting: December 17, 2004; Last Update: June 5, 2025.
• Spastic Paraplegia 3A
  Peter Hedera.
  Initial Posting: September 21, 2010; Last Update: June 18, 2020.
• Spastic Paraplegia 4
  Livia Parodi, Siri Lynne Rydning, Chantal Tallaksen, and Alexandra Durr.
  Initial Posting: April 17, 2003; Last Update: June 13, 2019.
• Spastic Paraplegia 7
  Giorgio Casari and Roberto Marconi.
  Initial Posting: August 24, 2006; Last Update: October 25, 2018.
• Spastic Paraplegia 8
  Inge A Meijer, Paul N Valdmanis, and Guy A Rouleau.
  Initial Posting: August 13, 2008; Last Update: May 21, 2020.
• Spastic Paraplegia 11
  Giovanni Stevanin.
  Initial Posting: March 27, 2008; Last Update: December 19, 2019.
• Spastic Paraplegia 15
  Darius Ebrahimi-Fakhari, Julian E Alecu, and Craig Blackstone.
  Initial Posting: May 27, 2021.
• Sphingosine Phosphate Lyase Insufficiency Syndrome
  Kathryn Nicole Weaver, Bonnie Sullivan, Friedhelm Hildebrandt, Jonathan Strober, Megan Cooper, Rathi Prasad, and Julie Saba.
  Initial Posting: October 15, 2020.
• Spinal and Bulbar Muscular Atrophy
  Albert La Spada.
  Initial Posting: February 26, 1999; Last Update: December 15, 2022.
• Spinal Muscular Atrophy
  Thomas W Prior, Meganne E Leach, and Erika L Finanger.
  Initial Posting: February 24, 2000; Last Update: September 19, 2024.
• Spinal Muscular Atrophy, X-Linked Infantile
  Lisa Baumbach-Reardon, JM Hunter, Mary Ellen Ahearn, and Miranda Pfautsch.
  Initial Posting: October 30, 2008; Last Revision: May 9, 2024.
• Spinocerebellar Ataxia Type 1
  Puneet Opal and Tetsuo Ashizawa.
  Initial Posting: October 1, 1998; Last Update: February 2, 2023.
• Spinocerebellar Ataxia Type 2
  Stefan M Pulst.
  Initial Posting: October 23, 1998; Last Update: February 14, 2019.
• Spinocerebellar Ataxia Type 3
  Henry Paulson and Vikram Shakkottai.
  Initial Posting: October 10, 1998; Last Update: June 4, 2020.
• Spinocerebellar Ataxia Type 4
  Andreas Puschmann, Sigurd Dobloug, Joel Wallenius, Klas Wictorin, and Sorina Gorcenco.
  Initial Posting: December 12, 2024.
• Spinocerebellar Ataxia Type 6
  Hannah L Casey and Christopher M Gomez.
  Initial Posting: October 23, 1998; Last Update: November 21, 2019.
• Spinocerebellar Ataxia Type 7
  Albert R La Spada.
  Initial Posting: August 27, 1998; Last Update: July 23, 2020.
• Spinocerebellar Ataxia Type 8
  John Douglas Cleary, SH Subramony, and Laura PW Ranum.
  Initial Posting: November 27, 2001; Last Update: April 22, 2021.
• Spinocerebellar Ataxia Type 10
  Tohru Matsuura and Tetsuo Ashizawa.
  Initial Posting: April 23, 2002; Last Update: September 19, 2019.
• Spinocerebellar Ataxia Type 11
  Zhongbo Chen, Arina Puzriakova, and Henry Houlden.
  Initial Posting: July 22, 2008; Last Update: October 31, 2019.
• Spinocerebellar Ataxia Type 13
  Michael F Waters.
  Initial Posting: November 9, 2006; Last Update: June 4, 2020.
• Spinocerebellar Ataxia Type 14
  Dong-Hui Chen, Thomas D Bird, and Wendy H Raskind.
  Initial Posting: January 28, 2005; Last Update: February 20, 2020.
• Spinocerebellar Ataxia Type 17
  Yasuko Toyoshima, Osamu Onodera, Mitsunori Yamada, Shoji Tsuji, and Hitoshi Takahashi.
  Initial Posting: March 29, 2005; Last Revision: July 28, 2022.
• Spinocerebellar Ataxia Type 20
  Elsdon Storey and RJM Gardner.
  Initial Posting: February 27, 2007; Last Update: April 18, 2019.
• Spinocerebellar Ataxia Type 37
  Antoni Matilla-Dueñas and Victor Volpini.
  Initial Posting: May 30, 2019.
• Spinocerebellar Ataxia Type 38
  Alfredo Brusco, Eleonora Di Gregorio, and Barbara Borroni.
  Initial Posting: July 11, 2019.
• Spinocerebellar Ataxia with Axonal Neuropathy Type 1
  Mustafa AM Salih, Hiroshi Takashima, and Cornelius F Boerkoel.
  Initial Posting: October 22, 2007; Last Update: June 30, 2022.
• Spondylocostal Dysostosis, Autosomal Recessive
  Peter D Turnpenny, Melissa Sloman, and Sally Dunwoodie.
  Initial Posting: August 25, 2009; Last Update: August 17, 2023.
• Spondylometaphyseal Dysplasia, Corner Fracture Type
  Jade England and Philippe M Campeau.
  Initial Posting: March 19, 2020; Last Update: May 22, 2025.
• Squalene Synthase Deficiency
  David Coman, Lisenka Vissers, Hans Waterham, John Christodoulou, Ron A Wevers, and James Pitt.
  Initial Posting: February 6, 2020.
• Stickler Syndrome
  Geert Mortier.
  Initial Posting: June 9, 2000; Last Update: September 7, 2023.
• Strømme Syndrome
  Stephanie KL Ho, Lai Ting Leung, Ho-ming Luk, and Ivan FM Lo.
  Initial Posting: November 10, 2022.
• Succinic Semialdehyde Dehydrogenase Deficiency
  Itay Tokatly Latzer, Phillip L Pearl, and Jean-Baptiste Roullet.
  Initial Posting: May 5, 2004; Last Update: January 9, 2025.

• T

• TANGO2 Deficiency
  Christina Y Miyake, Lindsay Burrage, Kevin Glinton, Kimberly Houck, Alfonso Hoyos-Martinez, Brett Graham, Yaping Yang, Brandy Rawls-Castillo, Fernando Scaglia, Claudia Soler-Alfonso, and Seema R Lalani.
  Initial Posting: January 25, 2018; Last Update: March 9, 2023.
• TARDBP-Related Amyotrophic Lateral Sclerosis-Frontotemporal Dementia
  Vaishnavi Manohar, Leon Crowley, and Jemeen Sreedharan.
  Initial Posting: April 23, 2009; Last Update: January 5, 2023.
• TBC1D24-Related Disorders
  Simona Balestrini, Philippe M Campeau, Davide Mei, Renzo Guerrini, and Sanjay Sisodiya.
  Initial Posting: February 26, 2015; Last Update: October 24, 2024.
• TBCK-Related Neurodevelopmental Disorder
  Xilma Ortiz-Gonzalez, Holly Dubbs, Kierstin Keller, and Emily Durham.
  Initial Posting: June 12, 2025.
• TCIRG1-Related Osteopetrosis
  Wade Jodeh, Imranul Alam, and Michael Econs.
  Initial Posting: August 28, 2025.
• TECPR2-Related Hereditary Sensory and Autonomic Neuropathy with Intellectual Disability
  Gali Heimer, Sonja Neuser, Bruria Ben-Zeev, and Darius Ebrahimi-Fakhari.
  Initial Posting: September 22, 2022.
• TEK-Related Venous Malformations
  Emmanuel Seront, Laurence M Boon, and Miikka Vikkula.
  Initial Posting: September 18, 2008; Last Update: March 2, 2023.
• TET3-Related Beck-Fahrner Syndrome
  Jill A Fahrner.
  Initial Posting: May 18, 2023.
• TFR2-Related Hemochromatosis
  Marco De Gobbi and Antonella Roetto.
  Initial Posting: August 29, 2005; Last Update: December 7, 2023.
• THOC6 Intellectual Disability Syndrome
  Gabrielle Lemire, A Micheil Innes, and Kym M Boycott.
  Initial Posting: August 13, 2020.
• TK2-Related Mitochondrial DNA Maintenance Defect, Myopathic Form
  Julia Wang, Ayman W El-Hattab, and Lee-Jun C Wong.
  Initial Posting: December 6, 2012; Last Update: July 26, 2018.
• TNF Receptor-Associated Periodic Fever Syndrome
  Natalie Deuitch, Cornelia Cudrici, Amanda Ombrello, and Ivona Aksentijevich.
  Initial Posting: November 10, 2022.
• TNXB-Related Classical-Like Ehlers-Danlos Syndrome
  Fleur S van Dijk, Neeti Ghali, Serwet Demirdas, and Duncan Baker.
  Initial Posting: September 15, 2022.
• TP63-Related Disorders
  V Reid Sutton and Hans van Bokhoven.
  Initial Posting: June 8, 2010; Last Update: April 1, 2021.
• TRIO-Related Neurodevelopmental Disorder
  Konstantinos Varvagiannis, Lisenka ELM Vissers, Diana Baralle, Bert BA de Vries, and Gabriella Gazdagh.
  Initial Posting: August 10, 2017; Last Update: March 23, 2023.
• TRMU Deficiency
  Michaela Reinhart, Colleen Muraresku, and Rebecca Ganetzky.
  Initial Posting: May 11, 2023.
• TRPM3-Related Neurodevelopmental Disorder
  David Dyment, Matthew Lines, and A Micheil Innes.
  Initial Posting: February 23, 2023.
• TSEN54 Pontocerebellar Hypoplasia
  Tessa van Dijk and Frank Baas.
  Initial Posting: September 8, 2009; Last Update: May 28, 2020.
• TUBB4A-Related Leukodystrophy
  Norah Nahhas, Alex Conant, Eline Hamilton, Julian Curiel, Cas Simons, Marjo van der Knaap, and Adeline Vanderver.
  Initial Posting: November 3, 2016.
• TXNL4A-Related Craniofacial Disorders
  Hermann-Josef Lüdecke and Dagmar Wieczorek.
  Initial Posting: July 14, 2016; Last Update: May 12, 2022.
• Tangier Disease
  John R Burnett, Amanda J Hooper, Sally PA McCormick, and Robert A Hegele.
  Initial Posting: November 21, 2019.
• Tatton-Brown-Rahman Syndrome
  Philip J Ostrowski and Katrina Tatton-Brown.
  Initial Posting: June 30, 2022.
• Thanatophoric Dysplasia
  Tegan French and Ravi Savarirayan.
  Initial Posting: May 21, 2004; Last Revision: May 18, 2023.
• Thiamine-Responsive Megaloblastic Anemia Syndrome
  Shuhei Sako, Toshiki Tsunogai, and Kimihiko Oishi.
  Initial Posting: October 24, 2003; Last Update: July 28, 2022.
• Thrombocytopenia Absent Radius Syndrome
  Florence Petit and Simon Boussion.
  Initial Posting: December 8, 2009; Last Revision: November 2, 2023.
• Treacher Collins Syndrome
  Mafalda Barbosa, Ethylin Wang Jabs, and Sara Huston.
  Initial Posting: July 20, 2004; Last Update: June 20, 2024.
• Trichohepatoenteric Syndrome
  Alexandre Fabre, Patrice Bourgeois, Charlène Chaix, Karine Bertaux, Olivier Goulet, and Catherine Badens.
  Initial Posting: January 11, 2018.
• Trichorhinophalangeal Syndrome
  Beyhan Tüysüz, Nilay Güneş, and Dilek Uludağ Alkaya.
  Initial Posting: April 20, 2017; Last Update: March 21, 2024.
• Troyer Syndrome
  Emma Baple, Jacob Day, Allison Newman, and Andrew Crosby.
  Initial Posting: November 16, 2004; Last Update: August 14, 2025.
• Tuberous Sclerosis Complex
  Hope Northrup, Mary Kay Koenig, Deborah A Pearson, and Kit Sing Au.
  Initial Posting: July 13, 1999; Last Update: August 1, 2024.
• Tubulinopathies Overview
  Nadia Bahi-Buisson and Camille Maillard.
  Initial Posting: March 24, 2016; Last Update: September 16, 2021.
• Type II Collagen Disorders Overview
  Pernille Axél Gregersen and Ravi Savarirayan.
  Initial Posting: April 25, 2019; Last Update: October 24, 2024.
• Tyrosine Hydroxylase Deficiency
  Yoshiaki Furukawa and Stephen Kish.
  Initial Posting: February 8, 2008; Last Update: May 11, 2017.
• Tyrosinemia Type I
  Can Ficicioglu.
  Initial Posting: July 24, 2006; Last Update: November 20, 2025.
• Tyrosinemia Type II
  Zahra Bayzaei, Seyed Mohsen Dehghani, and Bita Geramizadeh.
  Initial Posting: October 24, 2024.

• U

• UNC80 Deficiency
  Nuria C Bramswig and Maha S Zaki.
  Initial Posting: September 21, 2017; Last Update: May 18, 2023.
• Udd Distal Myopathy – Tibial Muscular Dystrophy
  Bjarne Udd and Peter Hackman.
  Initial Posting: February 17, 2005; Last Update: January 2, 2020.
• Uncomplicated (Pure) Hereditary Spastic Paraplegia Overview
  Peter Hedera.
  Initial Posting: August 15, 2000; Last Update: June 5, 2025.
• Urea Cycle Disorders Overview
  Kara L Simpson, Erin L MacLeod, Aadil Kakajiwala, Andrea L Gropman, and Nicholas Ah Mew.
  Initial Posting: April 29, 2003; Last Update: July 3, 2025.
• Urofacial Syndrome
  William G Newman, Adrian S Woolf, Glenda M Beaman, and Neil A Roberts.
  Initial Posting: August 22, 2013; Last Update: September 28, 2023.
• Usher Syndrome Type I
  Robert K Koenekoop, Moises A Arriaga, Karmen M Trzupek, and Jennifer J Lentz.
  Initial Posting: December 10, 1999; Last Revision: October 8, 2020.
• Usher Syndrome Type II
  Robert Koenekoop, Moises Arriaga, Karmen M Trzupek, and Jennifer Lentz.
  Initial Posting: December 10, 1999; Last Revision: March 23, 2023.

• V

• VEXAS Syndrome
  Jerome Hadjadj and David Beck.
  Initial Posting: May 15, 2025.
• VLDLR Cerebellar Hypoplasia
  Kym M Boycott, Stella K MacDonald, and Jillian S Parboosingh.
  Initial Posting: August 26, 2008; Last Update: February 27, 2020.
• VPS13A Disease
  Kevin Peikert, Carol Dobson-Stone, Luca Rampoldi, Gabriel Miltenberger-Miltenyi, Aaron Neiman, Pietro De Camilli, Andreas Hermann, Ruth H Walker, Anthony P Monaco, and Adrian Danek.
  Initial Posting: June 14, 2002; Last Update: March 30, 2023.
• VPS13D Movement Disorder
  Inge A Meijer.
  Initial Posting: February 21, 2019.
• VPS35-Related Parkinson Disease
  Jaroslaw Dulski, Owen A Ross, and Zbigniew K Wszolek.
  Initial Posting: August 10, 2017; Last Update: March 23, 2023.
• Variegate Porphyria
  Ashwani K Singal and Karl E Anderson.
  Initial Posting: February 14, 2013; Last Update: December 12, 2019.
• Vascular Ehlers-Danlos Syndrome
  Peter H Byers.
  Initial Posting: September 2, 1999; Last Update: April 10, 2025.
• Very Long-Chain Acyl-Coenzyme A Dehydrogenase Deficiency
  Nancy D Leslie and Sofia Saenz-Ayala.
  Initial Posting: May 28, 2009; Last Revision: August 7, 2025.
• Von Hippel-Lindau Syndrome
  Rachel S van Leeuwaarde, Saya Ahmad, Bernadette van Nesselrooij, Wouter Zandee, and Rachel H Giles.
  Initial Posting: May 17, 2000; Last Revision: May 1, 2025.
• Von Willebrand Disease
  Jill Johnsen.
  Initial Posting: June 4, 2009; Last Update: November 14, 2024.

• W

• WAC-Related Intellectual Disability
  Konstantinos Varvagiannis, Bert BA de Vries, and Lisenka ELM Vissers.
  Initial Posting: November 30, 2017.
• WARS2 Deficiency
  Magdalena Mroczek, Aynekin Busra, Henry Houlden, Stephanie Efthymiou, and Sara Nagy.
  Initial Posting: October 12, 2023.
• WAS-Related Disorders
  Sharat Chandra, Chinmayee B Nagaraj, Miao Sun, Shanmuganathan Chandrakasan, and Kejian Zhang.
  Initial Posting: September 30, 2004; Last Update: August 15, 2024.
• WDR26-Related Intellectual Disability
  Cara M Skraban, Katheryn L Grand, and Matthew A Deardorff.
  Initial Posting: April 25, 2019.
• WDR62 Primary Microcephaly
  Alain Verloes, Lyse Ruaud, Séverine Drunat, and Sandrine Passemard.
  Initial Posting: February 17, 2022.
• WFS1 Spectrum Disorder
  Timothy Barrett, Lisbeth Tranebjærg, Rajat Gupta, Liam McCarthy, Nanna Dahl Rendtorff, Denise Williams, Benjamin Wright, and Renuka Dias.
  Initial Posting: February 24, 2009; Last Update: December 1, 2022.
• WT1 Disorder
  Beata S Lipska-Ziętkiewicz.
  Initial Posting: April 30, 2020; Last Update: May 15, 2025.
• Waardenburg Syndrome Type I
  Jeff Mark Milunsky.
  Initial Posting: July 30, 2001; Last Update: October 20, 2022.
• Weill-Marchesani Syndrome
  Pauline Marzin, Valérie Cormier-Daire, and Ekaterini Tsilou.
  Initial Posting: November 1, 2007; Last Update: December 10, 2020.
• Weiss-Kruszka Syndrome
  Paul Kruszka.
  Initial Posting: October 31, 2019.
• Werner Syndrome
  Junko Oshima, George M Martin, and Fuki M Hisama.
  Initial Posting: December 2, 2002; Last Update: May 13, 2021.
• White-Sutton Syndrome
  Nurit Assia Batzir, Janson White, and V Reid Sutton.
  Initial Posting: September 16, 2021.
• Wiedemann-Steiner Syndrome
  Sarah E Sheppard and Fabiola Quintero-Rivera.
  Initial Posting: May 26, 2022.
• Williams Syndrome
  Colleen A Morris.
  Initial Posting: April 9, 1999; Last Update: April 13, 2023.
• Wilms Tumor Predisposition
  Joyce T Turner, Jack Brzezinski, and Jeffrey S Dome.
  Initial Posting: December 19, 2003; Last Update: March 24, 2022.
• Wilson Disease
  Karl Heinz Weiss and Michael Schilsky.
  Initial Posting: October 22, 1999; Last Update: January 12, 2023.
• Woodhouse-Sakati Syndrome
  Saeed A Bohlega and Ali Abusrair.
  Initial Posting: August 4, 2016; Last Update: July 8, 2021.

• X

• X-Linked Acrogigantism
  Donato Iacovazzo and Márta Korbonits.
  Initial Posting: February 1, 2018.
• X-Linked Adrenoleukodystrophy
  Gerald V Raymond, Ann B Moser, and Ali Fatemi.
  Initial Posting: March 26, 1999; Last Update: April 6, 2023.
• X-Linked Agammaglobulinemia
  CI Edvard Smith and Anna Berglöf.
  Initial Posting: April 5, 2001; Last Update: June 27, 2024.
• X-Linked Congenital Retinoschisis
  Paul A Sieving, Ian M MacDonald, and Stephanie Hoang.
  Initial Posting: October 24, 2003; Last Update: November 5, 2020.
• X-Linked Congenital Stationary Night Blindness
  Ian M MacDonald, Stephanie Hoang, and Sari Tuupanen.
  Initial Posting: January 16, 2008; Last Update: July 3, 2019.
• X-Linked Dystonia-Parkinsonism
  Virgilio Gerald H Evidente.
  Initial Posting: December 13, 2005; Last Update: February 15, 2018.
• X-Linked Hyper IgM Syndrome
  Clinton P Dunn and M Teresa de la Morena.
  Initial Posting: May 31, 2007; Last Update: February 20, 2020.
• X-Linked Hypophosphatemia
  Michaël R Laurent, Pol Harvengt, Geert R Mortier, and Detlef Böckenhauer.
  Initial Posting: February 9, 2012; Last Update: December 14, 2023.
• X-Linked Lymphoproliferative Disease
  Lauren Meyer, Melissa Hines, Kejian Zhang, and Kim E Nichols.
  Initial Posting: February 27, 2004; Last Update: May 16, 2024.
• X-Linked Myotubular Myopathy
  James J Dowling, Michael W Lawlor, and Soma Das.
  Initial Posting: February 25, 2002; Last Update: August 23, 2018.
• X-Linked Protoporphyria
  Manisha Balwani, Robert Desnick; Porphyrias Consortium of the NIH-Sponsored Rare Diseases Clinical Research Network.
  Initial Posting: February 14, 2013; Last Update: November 27, 2019.
• X-Linked Severe Combined Immunodeficiency
  Eric J Allenspach, David J Rawlings, Aleksandra Petrovic, and Karin Chen.
  Initial Posting: August 26, 2003; Last Update: August 5, 2021.
• X-Linked Spondyloepiphyseal Dysplasia Tarda
  George E Tiller.
  Initial Posting: November 1, 2001; Last Revision: April 6, 2023.
• Xeroderma Pigmentosum
  Kenneth H Kraemer, John J DiGiovanna, and Deborah Tamura.
  Initial Posting: June 20, 2003; Last Update: March 24, 2022.
• Xia-Gibbs Syndrome
  Varuna Chander, Michael Wangler, Richard Gibbs, and David Murdock.
  Initial Posting: December 9, 2021.
• Xq28 Duplication Syndrome, Int22h1/Int22h2 Mediated
  Rami A Ballout, Ayman W El-Hattab, Christian P Schaaf, and Sau Wai Cheung.
  Initial Posting: March 10, 2016; Last Update: September 4, 2025.

• Y

• Y Chromosome Infertility
  Yuting Fan and Sherman J Silber.
  Initial Posting: October 31, 2002; Last Update: August 1, 2019.
• YARS1 Deficiency
  Luisa Averdunk, Hua Wang, Eva MM Hoytema van Konijnenburg, Sabine A Fuchs, Nadra Nasser Samra, Hanna Mandel, and Anne Mei-Kwun Kwok.
  Initial Posting: July 3, 2025.
• YIF1B-Related Neurodevelopmental Disorder
  Eva Medico-Salsench, Namik Kaya, and Tahsin Stefan Barakat.
  Initial Posting: September 12, 2024.

• Z

• ZAP70-Related Combined Immunodeficiency
  Kelly Walkovich and Mark Vander Lugt.
  Initial Posting: October 20, 2009; Last Revision: September 23, 2021.
• Zellweger Spectrum Disorder
  Steven J Steinberg, Gerald V Raymond, Nancy E Braverman, and Ann B Moser.
  Initial Posting: December 12, 2003; Last Update: October 29, 2020.
• Zhu-Tokita-Takenouchi-Kim Syndrome
  Mari Mori, Mathieu Lemaire, Grace Raines, Brandon S Stone, and Eun-Young Erin Ahn.
  Initial Posting: September 25, 2025.
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