Question

In Marfan's syndrome, aortic aneurysm occurs most commonly in:

• A. Ascending aorta
• B. Descending aorta
• C. Abdominal aorta
• D. Arch of aorta

Hint:

Cystic medial necrosis hits the aortic root and ascending aorta first.

Answer 1

The Correct Option is A

Step 1: Marfan's syndrome is a connective tissue disorder caused by a fibrillin-1 (FBN1) gene defect. The cardiovascular lesions are the most life-threatening features, so the answer relates to the aortic segment most affected.

Step 2: The aortic media in Marfan's undergoes cystic medial necrosis (cystic medionecrosis). This loss of medial support causes progressive dilatation of the aortic valve ring and the root of the aorta, which lie in the ascending portion. Hence aneurysms occur most commonly in the ascending aorta, making option a correct.

Step 3: The dilatation produces severe aortic incompetence and predisposes to aortic dissection, a leading cause of death in these patients.

Step 4: The descending, arch, and abdominal segments can be involved but far less often than the ascending aorta and root, so options b, c, and d are wrong. Mitral valve prolapse with regurgitation is another classic Marfan lesion but is not what the question asks.