Congenital Heart Disease in Down Syndrome
Trisomy 21, Down syndrome, is one of a number of chromosomal abnormalities associated with congenital heart disease. Recent studies indicate that approximately 5% of all congenital heart defects are associated with some form of chromosomal abnormality, the majority of which are Down syndrome. Reports of the incidence of congenital heart disease in patients who have Down syndrome have varied, but it is commonly accepted to be 50%. Endocardial cushion defect and ventricular septal defects both have been reported as the "most common," but the majority of investigators accept the endocardial cushion defect as being the more frequent. The association between endocardial cushion defects and Down syndrome is so striking that when an endocardial cushion defect is diagnosed in an infant, the possibility of Down syndrome always should be considered.
