A 24-year-old man has recurrent sustained ventricular tachycardia with left bundle branch block morphology and superior axis. ECG shows epsilon waves in anterior precordial leads. His father died suddenly at 38. Histology of the right ventricular free wall shows replacement of myocardium by fibrofatty tissue. Mutation in which protein family underlies this condition?

• A Desmosomal proteins ✓
• B Sarcomeric proteins
• C Dystrophin
• D Lamin A/C

Explanation

Arrhythmogenic right ventricular cardiomyopathy is caused by mutations in desmosomal proteins, most commonly plakophilin-2, inherited in autosomal dominant fashion. Defective cell-to-cell adhesion leads to myocyte detachment and fibrofatty replacement of the right ventricle, creating a substrate for ventricular tachycardia and sudden death in young athletes. Sarcomere mutations cause hypertrophic cardiomyopathy, while dystrophin mutations cause Duchenne muscular dystrophy cardiomyopathy.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.