FBN1 and isolated ectopia lentis: Type 1 MFS (or classic type) is associated with the FBN-1 mutation, representing 90% of all cases, and has a wider spectrum of manifestations, including ectopia lentis, which, together with ascending aorta dilatation or dissection, is a major criteria in MFS’ diagnosis, while symptoms of type 2 MFS, which can be associated both with FBN-1 or transforming growth factor receptor β 1 or 2 (TGFBR1 or TGFBR2) mutations, affect only the skeletal and cardiovascular systems.