In Fuchs' endothelial corneal dystrophy (FECD), the protein responsible for accelerated endothelial cell apoptosis and guttata formation has been linked to mutations in which gene?

• A COL8A2 gene encoding collagen type VIII alpha-2 chain ✓
• B TGFBI (BIGH3 gene)
• C SLC4A11 gene encoding sodium-borate cotransporter
• D ZEB1/TCF8 gene encoding a zinc-finger transcription factor

Explanation

Early-onset FECD (rare, dominant) is caused by mutations in COL8A2 (collagen VIII alpha-2), which is a major structural component of Descemet's membrane. Late-onset FECD (common form, ~4% of population >40 years) is linked to TCF4 CTG18.1 trinucleotide repeat expansion (chromosome 18q21) and to ZEB1 mutations. SLC4A11 mutations cause congenital hereditary endothelial dystrophy (CHED), not FECD. TGFBI mutations cause granular, lattice, and Avellino dystrophies. Understanding the genetic basis is important because FECD shows autosomal dominant inheritance with variable expressivity.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.