Ostium primum atrial septal defect is associated with which condition?

• A. Down syndrome
• B. Marfan syndrome
• C. Ehlers-Danlos syndrome
• D. No systemic associations

Answer: (A)

Ostium primum ASD is a low defect in the interatrial septum at the site of the AV cushions and is part of endocardial cushion defects. This pattern is classically seen with Down syndrome (trisomy 21), where atrioventricular canal defects are a hallmark congenital heart finding. So the defect is associated with Down syndrome. Marfan and Ehlers-Danlos involve other common cardiac issues (like aortic root dilation or connective tissue–related valve problems) and do not have a specific strong association with ostium primum ASD.