In hypertrophic cardiomyopathy (HCM), the most common causative genetic mutation involves:

• A Dystrophin gene mutation causing X-linked dilated cardiomyopathy
• B SCN5A mutation causing ion channel dysfunction and arrhythmia
• C Lamin A/C (LMNA) mutation causing nuclear envelope dysfunction
• D Beta-myosin heavy chain (MYH7) or myosin-binding protein C (MYBPC3) mutations — sarcomere proteins ✓

Explanation

HCM is predominantly caused by autosomal dominant mutations in sarcomere protein genes; the most common are MYH7 (beta-myosin heavy chain) and MYBPC3 (myosin-binding protein C), accounting for approximately 70% of genotype-positive cases. These mutations cause hypercontractility and disorganized myofibril arrangement (myocyte disarray). Dystrophin mutations cause Duchenne/Becker or X-linked DCM. SCN5A mutations cause Brugada syndrome and Long QT syndrome. LMNA mutations cause DCM with conduction disease.

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

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Written and medically reviewed by the StethoPrep medical team.