Namely, Myh6 has been associated with dilated cardiomyopathy (MIM: 613252) and decreased contractile function68 with hypoplastic left heart syndrome (HLHS [MIM: 241550]),69 but is also associated with atrial septal defects (MIM: 614089) in humans.70 This evidence concerns the gene MYH6 and Abnormal cardiac septum morphology.