TheSTRC gene provides instructions for creating a protein calledstereocilin, named for its location outside the stereocilia cells in the inner ear. This protein is associated with thehair bundle of the sensory hair cells in the inner ear. The hair bundle is composed of stiffmicrovilli calledstereocilia and is involved withmechanoreception of sound waves. Stereocilia cells generate an electrical response to the vibrations of sound waves, crucial for normal hearing.
This gene is part of a tandem duplication on chromosome 15; the second copy is apseudogene. Impairment of theSTRC gene leads to the production of a non-functional stereocilin or prevents its production altogether. Consequently, this results in instability in the structure of stereocilia, hindering their optimal response to the passage of sound waves. In the end, the hair cells fail to convert sound waves into electrical potentials, causing hearing impairment. Hence, mutations in this gene cause autosomal recessivenon-syndromic deafness.[7][8]
Mutations inSTRC is the most common cause of moderatebilateral hearing loss, accounting for approximately 30% of cases.[9] The prevalence of hearing loss due to alterations in theSTRC gene is estimated at 1 in 1600.[10]
99% of the genetic alterations in the STRC gene associated with non-syndromic hearing loss involve largecopy number variations. Often, the alteration is a large deletion on chromosome 15, including several genes, among themSTRC. In some cases, this deletion includes theCATSPER2 gene, which can lead to fertility issues in males.
^"Human PubMed Reference:".National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:".National Center for Biotechnology Information, U.S. National Library of Medicine.
^Verpy E, Masmoudi S, Zwaenepoel I, Leibovici M, Hutchin TP, Del Castillo I, et al. (November 2001). "Mutations in a new gene encoding a protein of the hair bundle cause non-syndromic deafness at the DFNB16 locus".Nature Genetics.29 (3):345–349.doi:10.1038/ng726.PMID11687802.S2CID23062750.
