Fibulins in development and heritable disease

Fibulins are a family of five extracellular glycoproteins found in a variety of tissues in association with diverse supramolecular structures, including elastic fibers, basement membrane networks, fibronectin microfibrils, and proteoglycan aggregates. Studies of the developmental expression patterns have indicated that several fibulins are prominently expressed at sites of epithelial-mesenchymal transformations during embryogenesis; among these sites, the cardiovascular system has been analyzed in more detail. Gene targeting of fibulins in mice has provided important insights into their biological roles, and has led to the identification of gene mutations in a congenital disorder of humans, cutis laxa. Genetic linkage and molecular studies have also associated several fibulin genes with various human heritable disorders that affect a wide range of organs, including limb, eye, blood, and arteries. In this review, we discuss the role of fibulins in development, with an emphasis on the cardiovascular system, and their involvement in human genetic disease.