Overview Structure rich in proline, lysine, glycine unlike collagen, can exist in nonglycosylated forms fibrillin protein binds to tropoelastin to form elastic fibers Marfan's disease is caused by a defect in fibrillin presentation long extremities including fingers scoliosis myopia and lens dislocations upward (like a martian leaving for outer space) as opposed to a downward dislocation in homocystinuria mitral valve prolapse ↑ for aortic aneurism Function is an elastic protein found in tissues where stretch is needed lungs, dermis of the skin, large arteries, elastic ligaments, vocal cords, ligamenta flava of vertebrae desmosine interchain cross linking between lysine residues gives the protein its elastic stretch degraded by elastase α1-antitrypsin normally inhibits elastase class of protease inhibitors synthesized in the liver excess elastase activity caused by α1-antitrypsin (AAT) deficiency absent α1-globulin peak in serum protein electrophoresis autosomal codominant inheritence presentation panacinar emphysema worsened by smoking early onset smoking without AAT deficiency usually causes centriacinar emphysema cirrhosis Clinical Significance Disease Comments Marfan syndrome Almost exclusively AD Mutation in FBN gene encodes fibrillin-1 gene on chromosome 15 Patients are susceptible to aortic disease, MVP, lens dislocation, scoliosis, pectus deformity, arachnodactyly α1-antitrypsin deficiency Autosomal codominant inheritence α1-antitrypsin inhibits elastase Can lead to panacinar emphysema and hepatic disease