Ulnar Artery Aneurysm as a Late Sequela of Marfan Syndrome.

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations of the FBN1 gene encoding fibrillin-1, which leads to overexpression of transforming growth factor-β, increased hyaluronan deposition, and matrix metalloproteinase activity in the media of the aorta and other muscular arteries. Marfan syndrome patients present with connective tissue laxity and aneurysmal changes to muscular arteries. Successful medical and surgical intervention has prolonged the life expectancy of MFS patients, which can allow atypical presentations of the syndrome to manifest. We present a case of a 49-year-old man with MFS who developed an ulnar artery aneurysm that was treated by excision and vein grafting.