Cardiovascular abnormalities included aortic isthmus stenosis in the male patient (born to consanguineous parents) with a homozygous SMAD6 variant (p.[(Ile466Thr)];[(Ile466Thr)]), while the female proband, harbouring compound heterozygous SMAD6 variants (p.[(Phe357Ile)];[(Ser483Pro)]), had a dysplastic and stenotic pulmonary valve, dilated cardiomyopathy, narrowing of the proximal left pulmonary artery, stenosis of the left main coronary artery leading to ischaemia and a venous anomaly in the brain. This evidence concerns the gene SMAD6 and dilated cardiomyopathy.