Okur-Chung Neurodevelopmental Syndrome (OCNDS) is anultra-rare neurodevelopmental syndrome first discovered in 2016. The estimated prevalence is 1 in every 100,000 live births.[1] OCNDS is caused by pathogenic variants in theCSNK2A1 gene.
Dr. Volkan Okur andDr. Wendy Chung discovered OCNDS in 2016.[2]
Individuals with Okur–Chung neurodevelopmental syndrome (OCNDS) commonly show global developmental delay, intellectual disability, hypotonia, and speech and language impairment. Some individuals are non-verbal. Developmental milestones are often delayed. Independent walking is typically achieved later than average. Most children walk by 18 months in the general population, while the mean reported age in OCNDS is about 30.6 months.[3][4]. First spoken words also tend to occur later. Around 60% of affected individuals do not speak their first words until after 18 months.[4] Typical first word use is around 12 months in most children, with up to 16 months considered within the normal range.[5][6]
Neurological features are frequent.Global developmental delay andintellectual disability are commonly reported neurological symptoms.[4] Approximately a third of patients present with a smaller head circumference (microcephaly).[7]Seizures occur in roughly one-third of patients and may present as complex partial,grand mal,infantile spasms, petit mal, atonic drop attack, and simple partial seizures, with an average onset near 2 years of age.[4] Behavioral and neurodevelopmental conditions such asautism spectrum disorder,attention-deficit/hyperactivity disorder (ADHD), and behavioral dysregulation (e.g., aggression, tantrums) related to communication challenges have been reported.[8]
Musculoskeletal and growth-related findings includehypotonia as a common presentation.[4]Scoliosis andkyphosis can occur. Nearly half of affected individuals haveshort stature.[4] Some exhibit a partialgrowth hormone deficiency.[8]
Several other body systems may be involved. Gastrointestinal issues are common.Constipation is most frequently reported[4], and some infants experience feeding difficulties that can lead togastrostomy tube placement.[8] Immune-related issues include recurrent minor infections. Some individuals show low immunoglobulin levels (for example IIgG orIgA deficiency) and requireintravenous immunoglobulin treatment.[8] Ophthalmologic manifestations include astigmatism andstrabismus.[4][8]Genitourinary anomalies vary and can include ectopic kidney, duplicated renal collecting system, pelvicaliectasia, labial adhesions[8] , and undescended testes[4]. Cardiovascular findings reported in a minority of cases include pulmonary valve abnormalities,atrial septal defect,tetralogy of Fallot[8], andaortic root dilation.[4]
Dental anomalies have been described in primary teeth. Reported findings include cracked teeth, unusually long incisors, enamel defects, fused teeth, and microdontia.[9]
The majority of cases arede novo however,inherited cases have been observed.[10][7][11] Inheritance occurs via anautosomaldominant inheritance pattern.
OCNDS is a genetic disorder with an autosomal dominant pattern of inheritance. Most cases are sporadicmutations.[2][8] The causative gene isCSNK2A1, located onchromosome 20.CSNK2A1 encodes for the protein Casein Kinase 2 alpha 1 (CK2α), the alpha catalytic subunit of a criticalkinase protein in the body. Different types ofpathogenic variants exist in OCNDS including:[12]
Currently, OCNDS can only be diagnosed through genetic sequencing (e.g.,whole exome sequencing,whole genome sequencing, select panels at genetic testing labs).[8] Testing is initiated for individuals who have suggestive findings for OCNDS.
There is currently no curative treatment for OCNDS. Management focuses on supportive care and early intervention to address developmental, behavioral, and medical needs.[8] Children often receive speech, occupational, and physical therapy. Some may also benefit frommusic orequine-assisted therapy. Augmentative and alternative communication (AAC) devices are frequently used to support communication. Standard anti-seizure medications are used when epilepsy is present.[8] Many children require individualized educational support through an Individualized Education Program (IEP).[8] Ongoing surveillance is recommended to monitor growth, nutrition and feeding concerns, constipation, developmental progress, infections, sleep disturbances, vision issues, and emerging symptoms such as seizures or changes in motor, coordination, or behavioral functioning.[8]
OCNDS affects both males and females. The estimatedprevalence is 1 in 100,000.[1]
AnICD-10 Code has been proposed for OCNDS and is currently under review.[13]
Apatient advocacy organization exists to support individuals and families called the CSNK2A1 Foundation.[14]