Genetic disorder. Fbn1 gene controls connective tissue metabolism. If there are mutations or repeats, then marfa's will result. The symptoms are the result of malformed collagen. So dislocated lens in eye, heart valve problems, scoliosis, pneumothorax, artery problems may occur. Most cases are inherited, but occasionally marfan's occurs from a spontaneous mutation. This gene can be tested for in a blood specimen.