Marfan's syndrome is caused by recurrent de novo missense mutation in the fibrillin-1 gene. Fibrillin1 is a large glycoprotein that is a structural component of microfibrils. Fibrillin 1 is found in the zonular fibers of the lens, in the periosteum and elastin fibers of aoa. Defect in fibrillin gene accounts for the manifestations of marfans syndrome such as ectopia lentis, arachnodactyly and cardiovascular problems. Mutation of fibrillin 2 gene on chromosome 5 lead to causation of congenital contractural arachnodactyly.