In Marfan’s syndrome, Aoic aneurysm occurs most commonly in –
**Core Concept**
Marfan's syndrome is a genetic disorder affecting the body's connective tissue, which provides support and structure to various organs, bones, and other tissues. Aortic aneurysm in Marfan's syndrome is a consequence of the defective connective tissue, specifically the elastic fibers in the aortic media.
**Why the Correct Answer is Right**
The aortic aneurysm in Marfan's syndrome typically occurs at the level of the **sinus of Valsalva**, particularly at the **sinus of Valsalva of the right coronary sinus**. This is because the genetic defect affects the aortic root, leading to dilatation of the aortic sinuses. The weakened aortic wall is prone to aneurysm formation, which can lead to catastrophic complications such as aortic dissection or rupture.
**Why Each Wrong Option is Incorrect**
**Option A:** The ascending aorta is involved in Marfan's syndrome, but the aneurysm typically occurs at the level of the aortic sinuses, not the ascending aorta as a whole.
**Option B:** The descending aorta is also affected in Marfan's syndrome, but the aneurysm is more commonly associated with the ascending aorta.
**Option C:** The abdominal aorta is less commonly involved in Marfan's syndrome, and aneurysms in this location are more typically associated with other conditions such as hypertension or atherosclerosis.
**Clinical Pearl / High-Yield Fact**
In Marfan's syndrome, aortic aneurysms are often associated with a **dilated aortic root**, which can be detected on chest radiographs or echocardiography. Aneurysm repair or replacement may be necessary to prevent catastrophic complications.
**Correct Answer: C. Descending aorta.