We ascertained a group of individuals with DS and complete atrioventricular septal defect and sequenced 2 candidate genes for CHD: CRELD1, which is associated with atrioventricular septal defect in people with or without DS, and HEY2, whose mouse ortholog (Hey2) produces septal defects when mutated.
Of the several genes identified for CHD, CRELD1 is an important cell adhesion molecule crucial in cardiac development, which is known to cause atrioventricular septal defect in Down syndrome and also in sporadic forms of atrioventricular septal defect.