The most common genetic cause of non-syndromic congenital sensorineural hearing loss worldwide is:

• A PAX3 mutation causing Waardenburg syndrome
• B Mitochondrial 12S rRNA A1555G mutation
• C Mutation in GJB2 gene encoding connexin 26 ✓
• D SLC26A4 mutation encoding pendrin

Explanation

GJB2 mutations at the DFNB1 locus on chromosome 13q12 cause connexin 26 deficiency, disrupting potassium recycling in the cochlea. They account for a large proportion, up to half in some series, of childhood non-syndromic sensorineural deafness and are inherited autosomal recessively. The mitochondrial 12S rRNA C1555G mutation specifically predisposes to aminoglycoside-induced deafness, and SLC26C4 underlies Pendred syndrome, which includes thyroid goitre.

Reference: Cummings Otolaryngology Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.