HCM is conventionally understood as a cardiac disease inherited in an autosomal dominant fashion with incomplete penetrance. Over the past two decades, genetic research has established that HCM has considerable allelic and non-allelic heterogeneity. For the majority of patients, outside of its utility in pre-symptomatic screening, a genetic diagnosis has not made important contributions to clinical management. In large part, this is because most proband patients have apparently unique mutations, and because the fidelity between genotype and phenotype has been poor in families and for mutations studied thus far.
Over the last 20 years, the di
