FBN1 and Marfan syndrome: Fibrillin-1 is the main component of microfibrils and provides the scaffold for elastin deposition during the formation of elastic fibers.38 Mutation of the Fbn1gene causes Marfan’s syndrome, and cardiovascular complications including aortic aneurysm are the major cause of death in this syndrome.39 Fibrillin-1 and fibrillin-2 have differing functional roles.