46 Mass (mitral valve prolapse, aortic enlargement, skin and skeletal findings) syndrome is a genetic disorder of connective tissue caused by mutations in the fbn1 gene. connective tissue is the material between the cells of the body that gives tissues form and strength. symptoms include mitral valve prolapse, nearsightedness, borderline and non-progressive aortic enlargement, and skin and skeletal findings that overlap with those seen in marfan syndrome. treatment is based on the individual’s symptoms