Marfan syndrome in Wikipedia
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It uses material from the Wikipedia article "Marfan syndrome".
(Source - Retrieved 2006-09-07 14:18:44 from http://en.wikipedia.org/wiki/Marfan_syndrome)
Marfan syndrome is a connective tissue disorder characterized by unusually long limbs. The disease also affects other bodily structures — including the lungs, eyes, heart and blood vessels — in less obvious ways. It is named for Antoine Marfan, the French pediatrician who first described it in 1896.
Marfan syndrome received great public attention when the musical $RENT$ premiered in 1996. The day before the musical premiered off-Broadway, its writer, Jonathan Larson, died of an aortic dissection, which was determined to have been caused by Marfan syndrome.
Marfan syndrome is an autosomal dominant disorder that has been linked to the FBN1 gene on chromosome 15. FBN1 codes for a protein called fibrillin-1, which is essential for the formation of elastic fibers found in connective tissue. Marfan syndrome is also an example of a dominant negative mutation. Marfan syndrome is associated with incomplete penetrance, therefore not all persons carrying the mutation develop the disease. Without the structural support provided by fibrillin, many connective tissues are weakened, which can have severe consequences on support and stability. A related disease has been found in mice, and the study of mouse fibrillin synthesis and secretion, and connective tissue formation, has begun to further our understanding of Marfan syndrome in humans. For instance it has been found that simply reducing the level of normal fibrillin-1 causes the Marfan related disease in mice .
More recently, transforming growth factor β (TGFβ) has been shown to play an important role in Marfan syndrome. Fibrillin-1 binds TGFβ, inactivating it. In Marfan syndrome, reduced levels of fibrillin-1 allow TGFβ to damage the lungs and heart. New treatments for Marfan, using antagonists of TGFβ, are being investigated (Habashi et al., 2006 Science 312(5770):117-21).
Although genetic testing is available, a diagnosis is usually made solely on clinical findings.
Estimates indicate that perhaps 3 in 10,000 people (0.03 percent of the population) has Marfan syndrome. It affects all races and both sexes equally.
Most individuals with Marfan syndrome have another affected family member, but about 30 percent of cases are due to de novo genetic mutations. Genetic counseling is available for families who may be at risk for Marfan syndrome.
The most serious conditions associated with Marfan syndrome primarily involve the cardiovascular system. Marfan syndrome may cause leakage of the mitral or aortic valves that control the flow of blood through the heart. This may produce shortness of breath, an irregular pulse, and undue tiredness. Another complication is aortic aneurysm.
Marfan syndrome sufferers may grow to larger than normal height, and typically have long, slender limbs and fingers. Sometimes the fingers have a long, thin, spidery appearance known as arachnodactyly. In addition to affecting height and limb proportions, Marfan syndrome may produce other skeletal symptoms. Curvature of the spine (scoliosis) is a common problem, as is abnormal indentation (pectus excavatum) or protrusion (pectus carinatum) of the sternum. These symptoms may in turn cause unusual pressure on the heart and lungs. Other symptoms include; abnormal joint flexibility, high palates, small jaws, flat feet, stooped shoulders, and dislocation of the optic lens. Some people with Marfans have speech impediments as a result of the high palates and small jaws.
Nearsightedness or myopia is a common condition associated with Marfan syndrome. In addition, the weakening of connective tissue often causes detachment of the retina and/or displacement of the lens in one or both eyes.
Marfan syndrome can often be confused with Loeys-Dietz syndrome, a highly similar connective tissue disorder resulting from mutations in the TGF-beta receptor genes TGFBR1 or TGFBR2.
There is no cure for Marfan syndrome, but effective treatment allows many people with the disorder to live normally.
The heart conditions related to Marfan syndrome may not necessarily produce obvious symptoms. As a result, regular checkups by a cardiologist are needed to monitor cardiovascular health. Potential problems may be detected through echocardiography, which involves the use of ultrasound to study the heart valves and the aorta. Beta blockers have been used to control some of the complications such as aortic aneurysms. If the dilation of the aorta threatens to lead to rupture a composite aortic valve and graft may be implanted. Although aortic graft surgery is a serious undertaking it usually results in a good outcome and a satisfactory quality of life. Elective aortic valve/graft surgery is usually considered when aortic dilatation reaches 50 millimeters, but each case needs to be specifically evaluated by a qualified cardiologist. New valve-sparing surgical techniques are becoming more common. Rupture of the aorta, or aortic dissection, is the most common cause of sudden death among Marfan syndrome sufferers.
The skeletal and ocular manifestations of Marfan syndrome can also be serious, although not life-threatening. These symptoms are usually treated in the typical manner for the appropriate condition. This can also affect height, arm length, and life span.
The Nuss procedure is now being offered to people with Marfans syndrome to correct 'sunken chest' or (pectus excavatum).
Research in laboratory mice has suggested that the angiotensin II receptor antagonist losartan, which appears to block TGF-beta activity, can slow or halt the formation of aortic aneurysms in Marfan syndrome. A large clinical trial sponsored by the National Institutes of Health comparing the effects of losartan and atenolol on the aortas of Marfan patients is scheduled to begin in late 2006. 
Below is a list of prominent figures known or believed to have had Marfan syndrome (most are according to the U.S. National Marfan Foundation):
- Abraham Lincoln
- Vincent Schiavelli, actor
- Jonathan Larson, Tony Award-winning playwright (Rent)
- Flo Hyman, captain, U.S. Olympic Volleyball team, 1984 (silver medalist)
- Chris Patton, college basketball player (University of Maryland)
- Akhenaten, Egyptian pharaoh, who was possibly the father of King Tutankhamun
- Charles de Gaulle
- Sergei Rachmaninoff
- Niccolò Paganini
- Mary Queen of Scots
- John Tavener, composer
- Pauline de Rothschild, fashion designer, writer, tastemaker
- (possibly) Johnny Appleseed
- (possibly) Peter Crouch, England and Liverpool footballer
- (possibly) Kermit L. Hall, noted legal history scholar and university president
- Joey Ramone, singer
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