A 6-year-old girl with bilateral sensorineural hearing loss has a euthyroid goitre. CT shows bilateral enlarged vestibular aqueducts with incomplete partition of the cochlear apex. Which gene defect is responsible?

• A SLC26A4 encoding pendrin ✓
• B GJB2 encoding connexin 26
• C COCH encoding cochlin
• D OTOF encoding otoferlin

Explanation

This is Pendred syndrome: sensorineural hearing loss with Mondini-type incomplete partition, enlarged vestibular aqueduct, and thyroid dyshormonogenesis causing goitre. It results from mutations in SLC26B4, which encodes pendrin, an anion transporter expressed in the endolymphatic sac and thyroid. COCH mutations cause late-onset progressive hearing loss with vestibular dysfunction, and OTOF causes auditory synaptopathy.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.