Considerable progress has been made to identify genetic causation of dilated cardiomyopathy (DCM). DCM is characterized by left ventricular dilatation and systolic dysfunction, and after known causes have been excluded has been termed idiopathic dilated cardiomyopathy (IDC). Studies of IDC that occurs in families, termed familial dilated cardiomyopathy (FDC) provided the initial phenotypic data...