Marfan's syndrome most commonly involves?

Ascending aoa REF: Cardiac surgery in adults 3' ed by lawrence H.Cohn chapter 46 Seventy-five to eighty-five percent of patients with Marfan syndrome have dilation of the aoic sinuses and annulus in addition to the ascending aoa. This morphology, referred to as annuloaoic ectasia, is the classic presentation of Marfan syndrome, but can occur in the absence of a known connective tissue disorder. Because of the frequent aoic root involvement, aoic insufficiency is common. One third of patients with Marfan syndrome also have mitral regurgitation.