Hypertrophic cardiomyopathy is the most common inherited cardiomyopathy, with a prevalence of 1:200 to 1:500. Cardiac amyloidosis, another cardiomyopathy caused by myocardial deposition of abnormally folded TTR protein, can be acquired or hereditary. The presence of pathogenic TTR gene variants in patients with phenotypic HCM is an underrecognized and clinically important entity.