Hypertrophic Cardiomyopathy in the Era of Genomic Medicine

Hypertrophic cardiomyopathy (HCM) is a relatively common, primary disorder of the myocardium characterized by unexplained left ventricular hypertrophy affecting perhaps as many as 1 in 500 people. HCM is underscored by profound phenotypic and genotypic heterogeneity, with currently more than 20 genes associated with HCM. The underlying genetic mechanism for approximately 30%-60% of HCM remains elusive. Although many genotype-phenotype relationships have been observed, only a few carry enough clinical significance to aid physicians predicting genotype, course, and prognosis of the disease. Current treatment for HCM is aimed at symptom relief, but (animal) studies and clinical trials are underway to test (genotype-specific) pharmacologic treatments for prevention or regression of cardiac hypertrophy. This chapter details the clinical presentation of HCM, its genetic and nongenetic predisposition, important genotype-phenotype relationships, implications for genetic counseling and family screening, and treatment options for the disease.