FBN1 and mitral valve prolapse: FBN1 mutations can be found in many other conditions that may or may not overlap with Marfan syndrome such as skin and skeletal findings (Shprintzen-Goldberg syndrome)[21], syndrome of mitral valve prolapse, myopia, borderline aortic enlargement, skin and skeletal findings, Marfanoid habitus and isolated ectopia lentis.