Thirty four years later, abundance of fibrillin in these two tissues directed attention to this protein as a possible defect. Immunofluorescence study showed deficiency of elastin associated microfibrillar fibers in Marfan skin. Fibrillin is a glycoprotein member of the microfibrillar component of elastic fiber system. Study of fibrillin synthesis, secretion and incorporation in fibroblasts from 26 patients with Marfan syndrome 7 synthesized half normal amount and secreted it normally 7 synthesized normal amount but secreted it less efficiently 8 synthesized and secreted normally, but failed to incorporate 4 were indistinguishable from normal, control cells Fibrillin also present in periosteum. Skeletal defects of long limbs and digits, chest abnormalities, probably result from uncontrolled longitudinal growth of tubular bones in limbs, fingers and ribs.
Monoclonal antibodies localize in most all connective tissue matrices.
Mutations prove fibrillin to be the Marfan gene. Gene is 110 Kbp with 65 exons Protein is 2871 amino acids long. 8 cysteine rich TGF domains interrupt tandem EGF repeats. Proline rich domain. Carboxy terminal region.