Marfan syndrome is a systemic connective tissue disorder with a frequency of 2 to 3 in 10,000. The disorder is characterized by manifestations involving the cardiovascular, skeletal,and ocular systems. Current diagnostic criteria are based on the involvement of above organ systems and family history. Cardiovascular manifestations include mitral valve prolapse,progressive aortic root enlargement, and ascending aortic aneurysms,possibly leading to aortic regurgitation, dissection, or rupture. Some characteristic skeletal manifestations of this syndrome include a disproportional increase of linear bone growth resulting in malformations of the digits (arachnodactyly), craniofacial abnormalities, pectus excavatum/carinatum, and scoliosis.
A common ocular involvement is severe myopia and lens dislocation in one or both eyes (ectopia lentis). Marfan syndrome is an autosomal dominant disorder caused by fibrillin-1 gene mutations encoding for the extracellular matrix protein fibrillin (Fbn-1). Fibrillin is an integral component of both elastic and nonelastic connective tissue. The mechanism of fibrillin mutation in Marfan syndrome remains unclear. However, animal models of Fbn-1 have demonstrated a role of TGF-beta signaling. In some patients with phenotypes similar to Marfan syndrome but without fibrillin-1 gene mutations, TGF-beta receptor mutations have been identified, suggesting a significant role of TGF-beta pathway in the pathogenesis of Marfan syndrome features.
Aortic root involvement remains the leading cause of death in patients with Marfan syndrome. Echocardiography is recommended to routinely screen and to follow aortic root dilation. In addition, all first-degree relatives of the family should have screening echocardiography. Patients should be advised against strenuous exercises. Medical therapy forMarfan syndrome includes beta-blockers to reduce myocardial contractility and pulse pressure. Animal models ofMarfan syndrome have demonstrated a possible benefit of losartan in preventing progression of the disease by inhibiting the TGF-beta pathway and this therapy is the subject of an active clinical trial. Elective aortic root replacement remains the therapy of choice once the aortic root becomes significantly enlarged. Marfan patients who become pregnant need to be counseled not only about the 50% chance of transmitting the disease but also the substantially increased risk of aortic rupture/dissection during and after pregnancy. Important components of Marfan syndrome counseling are consideration of contraception and pregnancy management.