Which statement best describes the relationship between Down syndrome and endocardial cushion defects?

Which statement best describes the relationship between Down syndrome and endocardial cushion defects?

• A. They are an uncommon association
• B. They are a common congenital heart defect in Down syndrome
• C. They never occur together
• D. They always cause pulmonary hypertension by age 2

Answer: (B)

Down syndrome has a strong association with endocardial cushion defects, which are essentially atrioventricular septal defects. These defects arise from abnormal formation and fusion of the endocardial cushions during cardiac development, leading to a primum-type atrial septal defect with a ventricular septal defect and a common or cleft-left AV valve. Because of this embryologic link, endocardial cushion defects are the most characteristic and commonly seen congenital heart defect in Down syndrome. So the statement that these endocardial cushion defects are a common congenital heart defect in Down syndrome is accurate. It’s not an uncommon or rare association, and while uncorrected lesions can lead to pulmonary hypertension, it does not occur universally or by age two in every affected child.

Down syndrome has a strong association with endocardial cushion defects, which are essentially atrioventricular septal defects. These defects arise from abnormal formation and fusion of the endocardial cushions during cardiac development, leading to a primum-type atrial septal defect with a ventricular septal defect and a common or cleft-left AV valve. Because of this embryologic link, endocardial cushion defects are the most characteristic and commonly seen congenital heart defect in Down syndrome.

So the statement that these endocardial cushion defects are a common congenital heart defect in Down syndrome is accurate. It’s not an uncommon or rare association, and while uncorrected lesions can lead to pulmonary hypertension, it does not occur universally or by age two in every affected child.