Hypertrophic cardiomyopathy is commonly caused by mutations in which of the following?

Hypertrophic cardiomyopathy is commonly caused by mutations in which of the following?

• A. Desmosomal proteins
• B. Myosin heavy chain
• C. Sarcomere proteins
• D. Dystrophin

Answer: (C)

Hypertrophic cardiomyopathy mainly stems from mutations that disrupt the heart’s contractile machinery. The sarcomere—the fundamental contractile unit of cardiac muscle—depends on properly functioning proteins such as myosin heavy chain, myosin-binding protein C, troponin, and tropomyosin. When the genes encoding these sarcomeric proteins are mutated, the contractile apparatus works abnormally, triggering compensatory cellular remodeling that leads to myocardial hypertrophy and the characteristic disorganized myocytes. This makes sarcomere proteins the central deficit in classic HCM, explaining why this category is the correct choice. In contrast, desmosomal proteins are more associated with arrhythmogenic cardiomyopathy, and dystrophin mutations relate to dilated cardiomyopathy seen in muscular dystrophy, not the hypertrophic form.

Hypertrophic cardiomyopathy mainly stems from mutations that disrupt the heart’s contractile machinery. The sarcomere—the fundamental contractile unit of cardiac muscle—depends on properly functioning proteins such as myosin heavy chain, myosin-binding protein C, troponin, and tropomyosin. When the genes encoding these sarcomeric proteins are mutated, the contractile apparatus works abnormally, triggering compensatory cellular remodeling that leads to myocardial hypertrophy and the characteristic disorganized myocytes. This makes sarcomere proteins the central deficit in classic HCM, explaining why this category is the correct choice. In contrast, desmosomal proteins are more associated with arrhythmogenic cardiomyopathy, and dystrophin mutations relate to dilated cardiomyopathy seen in muscular dystrophy, not the hypertrophic form.