Marfan syndrome
Marfan syndrome is a connective tissue disorder, affecting many structures, including the skeleton, lungs, eyes, heart and blood vessels. It is named for the French pediatrician Antonin Marfan, who first described it in 1896. The disease is characterized by unusually long limbs, and is believed to have affected Abraham Lincoln and violinist Nicolo Paganini. Osama bin Laden is also rumored to have Marfan syndrome.
Marfan syndrome is an autosomal dominant disorder that has been linked to the FBN1 gene on chromosome 15. FBN1 encodes a protein called fibrillin, which is essential for the formation of elastic fibres found in connective tissue. Without the structural support provided by fibrillin, many coonective tissues are weakened, which can have severe consequences on support and stability. A related disease has been found in mice, and it is hoped that the study of mouse fibrillin synthesis and secretion, and connective tissue formation, will further our understanding of Marfan syndrome in humans.
Estimates indicate that perhaps 1 in 10,000 people has Marfan syndrome. There is no cure, but effective treatment allows many people with the disorder to live normally. It affects all races and both sexes equally.
Symptoms
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. Due to the spidery appearance of the fingers, Marfan syndrome has also been 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 or protrusion of the sternum. These symptoms may in turn cause unusual pressure on the heart and lungs.
Nearsightedness or myopia is a common condition associated with Marfan syndrome. In addition, the weakening of connective tissue often causes detachment of the retina.
Treatment
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 nickel-titanium stent may be inserted. 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.
