In Fuchs endothelial corneal dystrophy, the primary molecular abnormality involves mutations most commonly in:

• A TCF4 (transcription factor 4) gene with CTG trinucleotide repeat expansion ✓
• B TGFB1 gene affecting transforming growth factor beta signaling
• C SLC4A11 gene encoding a sodium-borate cotransporter in endothelial cells
• D COL8A2 gene encoding collagen VIII affecting Descemet membrane formation

Explanation

The most common genetic basis for late-onset Fuchs endothelial corneal dystrophy is a CTG trinucleotide repeat expansion in the TCF4 gene (encoding transcription factor 4), found in approximately 75% of affected patients. This repeat expansion causes aberrant splicing. COL8A2 mutations cause early-onset Fuchs and Posterior Polymorphous Corneal Dystrophy. SLC4A11 mutations cause congenital hereditary endothelial dystrophy. Understanding the molecular basis is relevant for genetic counseling.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.