Results We identified mutations in 25 of 51 affected children without family histories of cardiomyopathy and in 21 of 33 affected children with familial cardiomyopathy.

Hypertrophic cardiomyopathy is not related to ischemic heart disease but 50% of cases are familial and may be related to genetic mutations in genes encoding for cardiac contractile elements.

Familial hypertrophic cardiomyopathy (FHCM) is a genetically heterogeneous cardiac disease transmitted as an autosomal dominant trait. It is the leading cause of sudden cardiac death (SCD) in youth.