Hypertrophic cardiomyopathy (HCM) is an inherited condition in which mutations in genes that encode the sarcomere proteins in the heart cause an abnormal thickening of that muscle, with no known cure. In black patients, HCM is usually diagnosed at a younger age and accompanied by a greater burden of symptomatic heart failure. These patients, however, are not well represented in surveys of the condition, which tend to focus on white patients.