Connexin 26 (GJB2) gene mutations account for what proportion of congenital non-syndromic autosomal recessive sensorineural hearing loss?
- A 10–15%
- B 20–25%
- C 50% ✓
- D More than 70%
Correct answer: C. 50%
Explanation
GJB2 mutations (particularly 35delG and 167delT) account for approximately 50% of all cases of non-syndromic autosomal recessive sensorineural hearing loss in many populations. Connexin 26 forms gap junctions critical for potassium ion recycling in the cochlea. In India, the W24X mutation is particularly prevalent. Knowledge of the specific mutation guides genetic counselling and predicts phenotypic severity.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.