A 7-year-old girl with bilateral sensorineural hearing loss since early childhood develops an anterior neck swelling. She is clinically and biochemically euthyroid. High resolution CT of the temporal bone shows bilateral dilatation of the vestibular aqueduct. Which gene mutation is most likely responsible?

• A GJB2 encoding connexin 26
• B OTOF
• C MYO7A
• D SLC26A4 encoding pendrin ✓

Explanation

Pendred syndrome is autosomal recessive sensorineural hearing loss with euthyroid goitre due to defective iodide organification, caused by SLC26A4 mutations encoding pendrin, an anion transporter. The classical temporal bone findings are enlarged vestibular aqueduct and Mondini dysplasia. GJB2 mutations cause non-syndromic recessive deafness without thyroid disease or inner ear malformation, which kills the most tempting distractor. MYO7A is linked to Usher syndrome.

Reference: Scott-Brown's Otorhinolaryngology Head and Neck Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.