This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Paediatrics, Subject name: Pediatrics
[{'content': 'The child shown below is suffering from a congenital hea disease. Which congenital hea defect is seen most commonly seen in these children? \nSelect and explain. \nA. Patent ductus aeriosus, B. Atrial septal defect, C. Atrioventricular septal defect, D. Ventricular septal defect', 'role': 'user'}, {'content': "Answer: C \nExplanation: This child is suffering from Down syndrome. Impoant 'must know' facts about Down syndrome: - Trisomy 21 - MC - d/t maternal meiotic non-dysjunction - Risk increase with increase in mother's age - QMc hea disease in Down syndrome - AVSD (Atrioventricular septal defect) aka Endocardial cushion defect", 'role': 'assistant'}]