ABCC9 and familial dilated cardiomyopathy: None of the controls genotyped (n = 398) were homozygous for the variant, but 69 were heterozygous carriers, consistent with autosomal recessive inheritance with complete penetrance (p = 4 × 10−42 for the association of homozygosity for ABCC9 p.R1186Q with SCDY/DCM).