Hypertrophic cardiomyopathy is most often caused by mutations in which cardiac components?

Hypertrophic cardiomyopathy is most often caused by mutations in which cardiac components?

• A. Ion channels
• B. Sarcomere proteins
• C. Cytoskeletal proteins
• D. Gap junctions

Answer: (B)

Hypertrophic cardiomyopathy is driven by mutations in the sarcomere proteins—the contractile units of the heart muscle. When these sarcomeric components are altered, force generation and calcium handling change in a way that triggers a maladaptive, adaptive hypertrophic response, leading to the characteristic thickened ventricular walls and diastolic dysfunction. Common affected genes include those encoding beta-myosin heavy chain and myosin-binding protein C, among others, which is why sarcomere protein mutations are the classic cause of HCM. In contrast, ion channel mutations produce electrical disorders, cytoskeletal protein defects relate to different cardiomyopathies, and gap junction issues affect conduction rather than driving the hypertrophic remodeling seen in HCM.

Hypertrophic cardiomyopathy is driven by mutations in the sarcomere proteins—the contractile units of the heart muscle. When these sarcomeric components are altered, force generation and calcium handling change in a way that triggers a maladaptive, adaptive hypertrophic response, leading to the characteristic thickened ventricular walls and diastolic dysfunction. Common affected genes include those encoding beta-myosin heavy chain and myosin-binding protein C, among others, which is why sarcomere protein mutations are the classic cause of HCM. In contrast, ion channel mutations produce electrical disorders, cytoskeletal protein defects relate to different cardiomyopathies, and gap junction issues affect conduction rather than driving the hypertrophic remodeling seen in HCM.