Transforming Growth Factor Beta (TGF-β) is a protein that controls proliferation, cellular differentiation, and other functions in most cells. TGF-β levels play a major role in the pathogenesis of Marfan syndrome, a disease characterized by disproportionate height, long extremities, lens dislocation in the eyes and heart complications such as mitral valve prolapse and aortic enlargement increasing the likelihood of aortic dissection. While the underlying defect in Marfan syndrome is faulty synthesis of the glycoprotein fibrillin I, normally an important component of elastic fibers it has been shown that the Marfan syndrome phenotype can be relieved by addition of a TGF-β antagonist in affected mice. This suggest that while the symptoms of Marfan syndrome may seem consistent with a connective tissue disorder, the mechanism is more likely related to reduced sequestration of TGF-β by fibrillin.
