“…There is a wide spectrum of CHD in patients with T21. Atrioventricular septal defect (AVSD) is the most frequent CHD in patients with T21 (30%-60%), [4][5][6]9,11,12 followed by atrial (16%-21%), 4,6,8,12 and ventricular septal defect (VSD) (14%-27%), [4][5][6]8,9,12 tetralogy of Fallot (2%-11%), 5,8,12 patent arterial duct (6%), 5 coarctation of aorta (CoA) (0.3%), 8 and bicuspid aortic valve (BAV) (0.5%-2%). 5,8 Some of the CHD lesions could be isolated or combined with other types of CHD.…”