Partial Sequence of a Candidate Gene for the Marfan Syndrome

Fibrillin is a large (relative molecular mass 350,000) glycoprotein which can be isolated from fibroblast cell cultures and is a component of the microfibrils that are ubiquitous in the connective tissue space. The microfibrils of the suspensory ligament of the lens as well as the elastic fibre microfibrils of the blood vessel wall are composed of fibrillin. The ocular and cardiovascular manifestations of the Marfan syndrome are consistent with a defect in the gene coding for a structural constituent of these connective tissues. Immunohistological experiments have recently implicated fibrillin microfibrils in the pathogenesis of the Marfan syndrome. Genetic linkage data localizing the Marfan gene to chromosome 15 and the in situ hybridization of fibrillin complementary DNA to 15q21.1 together support fibrillin as a candidate Marfan gene. As a first step towards investigating the function of fibrillin in the architecture and development of connective tissues and its relationship to the Marfan syndrome, we report the cloning and partial sequencing of fibrillin cDNA.