Marfan syndrome (MFS) is a dominant inherited connective tissue disease. It has variable clinical manifestations and affects a number of systems, such as the cardiovascular system, eyes, skeletal, lung, skin etc. Fibrillin-1（FBN1）gene mutations are found in approximately 90% patients. The abnormal proteins originated from the mutant gene play a dominant negative effect on normal proteins or change their susceptibility of protease, which leads to the change of connective tissue. This paper reports the clinical data of a patient with Marfan syndrome accompanied by pituitary adenomas and reviews related literatures at home and abroad, to explore its pathogenesis. 马凡综合征（MFS）是一种少见的常染色体显性遗传的结缔组织病，临床表现多种多样，主要累及心血管、骨骼、眼、肺、皮肤等。目前研究认为约90%的MFS是由FBN1基因突变引起，其产生的异常原纤蛋白1通过对正常原纤蛋白1产生显性负效应活或本身对蛋白水解酶敏感性改变等机制导致全身结缔组织病。本文结合我院收治的1例马凡综合征合并垂体瘤患者的临床资料及国内外文献，更好的了解其发病机制
