TBX5 and familial dilated cardiomyopathy: Familial CCD can occur in the context of a structural heart disease, such as LMNA-associated DCM or complex congenital heart diseases (usually due to mutations in genes regulating cardiac development like Nkx2.5, GATA4, TBX5), or in a structurally normal heart (isolated CCD); in the latter case, variants of SCN5A and TRPM4 are the most found [4,6].