Adapted from The National Marfan Foundation Fact Sheet
Find out more about the Comprehensive Marfan Center at the Johns Hopkins Heart and Vascular Institute.
What is Marfan syndrome?
Marfan syndrome is a genetic disorder of the connective tissue that affects many organ systems, including the skeleton, lungs, eyes, heart and blood vessels. The condition affects both men and women of any race or ethnic group. It is estimated that at least 200,000 people in the United States have Marfan syndrome or a related connective tissue disorder.
What medical problems are associated with Marfan syndrome?
- The Cardiovascular System
The most serious problems associated with Marfan syndrome involve the cardiovascular system. The aorta, the main artery carrying blood away from the heart, is generally wider and more fragile in patients with Marfan syndrome. This widening is progressive and can cause leakage of the aortic valve or a tear (dissection) in the aorta wall. When the aorta becomes greatly widened, or tears, surgical repair is necessary. The two leaflets of the mitral valve may billow backwards when the heart contracts (mitral valve prolapse). This can lead to leakage of the mitral valve or irregular heart rhythm.
- The Skeleton
Skeletal manifestations common in people with Marfan syndrome include curvature of the spine (scoliosis), abnormally shaped chest (pectus deformity), loose jointedness and disproportionate growth usually, but not always, resulting in tall stature.
- The Eyes
People with Marfan syndrome are often near-sighted (myopic). In addition, about 50 percent have a dislocation of the ocular lens.
How is Marfan syndrome diagnosed?
People with Marfan syndrome exhibit different combinations of symptoms, so physicians arrive at a diagnosis through a number of tests and examinations. Because symptoms of Marfan syndrome overlap with other related connective tissue disorders, it is vitally important that your physicians be knowledgeable about Marfan syndrome. Tests include:
- Echocardiogram—a sound-wave picture of the heart and aorta—by a cardiologist.
- Slit-lamp examination by an ophthalmologist to check for dislocation of the ocular lens.
- Complete family history to determine other heart, skeletal or eye conditions among relatives.
- Skeletal examination by an orthopedist.
- Genetic test for a mutation in FBN1, the fibrillin-1 gene. Fibrillin is a component of microfibrils, a group of proteins that add strength and elasticity to connective tissue. A genetic mutation is found in 90 to 95 percent of people with Marfan syndrome.
How is Marfan syndrome treated?
People affected by Marfan syndrome should be treated by a physician familiar with the condition and with how it affects all body systems. There is no cure for the disorder yet, but careful medical management can greatly improve the prognosis and lengthen the life span.
Every affected person should work closely with their physician(s) for a customized treatment plan. In general, treatment includes the following:
- Annual echocardiogram to monitor the size and function of the heart and aorta.
- Initial eye examination with a slit lamp to detect lens dislocation, with periodic follow-up with an ophthalmologist.
- Careful monitoring of the skeletal system, especially during childhood and adolescence.
- Beta-blocker medications to lower blood pressure and therefore reduce stress on the aorta.
- Antibiotics prior to dental or genito-urinary procedures to reduce the risk of infection in people who experience mitral valve prolapse or who have artificial heart valves.
People who have had aortic surgery must take blood thinning medication. They also need to take antibiotics by injection before dental work, and in other situations in which bacteria could enter the blood stream. (Guidelines for Endocarditis Prophylaxis for People with Marfan Syndrome Who Have Had Cardiac Surgery, NMF Professional Advisory Board, June 1991).
- Lifestyle adaptations, such as the avoidance of strenuous exercise and contact sports—often necessary to reduce the risk of injury to the aorta.
What causes Marfan syndrome?
Marfan syndrome is caused by a mutation of FBN1, the fibrillin-1 gene. The mutation may be a sequencing change, deletion or duplication of proteins within the gene. Usually, this gene is inherited from a parent who is also affected. But around one-quarter of the cases are due to a spontaneous mutation. Marfan syndrome is autosomal dominant, indicating that a child of someone with the condition has a 50-50 chance of inheriting it.