<prompt> Most common hea lesion in down syndromeASD with ostium primumASD with ostium secundumVSDCoaection of aoa  <response>: Ans. is a i.e., ASD with ostium primum About 40 children with down syndrome have congenital hea disease. Endocardial cushion defect ASD with ostium primum account for 40-60 of cases. 