A 7-year-old boy presents with night blindness for 2 years. Fundus examination shows bone-spicule pigmentation in the mid-periphery, waxy pallor of the optic disc, and attenuated retinal arterioles. Electroretinogram shows markedly reduced scotopic and photopic responses. Which gene mutation is most commonly associated with autosomal dominant retinitis pigmentosa?

• A RHO (rhodopsin) gene ✓
• B RPGR gene
• C USH2A gene
• D RPE65 gene

Explanation

Rhodopsin (RHO) gene mutations are the most common cause of autosomal dominant retinitis pigmentosa, accounting for approximately 20-30% of AD cases. RPGR mutations cause X-linked RP (most severe form). USH2A causes Usher syndrome type 2 (autosomal recessive). RPE65 mutations cause Leber congenital amaurosis and autosomal recessive RP.

Reference: Ryan's Retina, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.