<prompt> The complications of Down syndrome include:VSDALLHypothyroidismAll of the above  <response>: Complications of Down syndrome are: Congenital cardiac defects Most common is ventricular septal defect. Increased risk of leukemia particularly ALL more commonly and specifically the megakaryoblastic form of AML M7-AML. Hypothyroidism. Reduced fertility in females Males are totally infertile. Increased risk of respiratory tract infections. 