Marfan Syndrome

By Tim Taylor

Inherited condition

The primary purpose of connective tissue is to hold the body together and provide a framework for growth and development. Marfan syndrome is an inherited condition that affects the connective tissue, causing complications that can be mild to severe and, in some cases, can be life threatening. About one in every 5,000 people in the United States have Marfan syndrome, which can affect men, women and children of all races and ethnic groups. Connective tissue holds the body together and provides support to many structures throughout the body. For those with Marfan syndrome, the connective tissue isn’t normal. As a result, many body systems are affected, including the heart, blood vessels, bones, tendons, cartilage, eyes, nervous system, skin and lungs. Named after Antoine Marfan, who first described the condition in 1896, the disorder is present at birth but may not be diagnosed until adolescence or young adulthood.

Defect in gene

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The condition known as Marfan syndrome is caused by a defect in the gene that encodes the structure of fibrillin and the elastic fibers, a major component of connective tissue. This gene is called fibrillin-1 or FBN1. In most cases, Marfan syndrome is inherited. The pattern is called “autosomal dominant,” meaning that it occurs equally in men and women and can be inherited from just one parent with Marfan syndrome. People who have Marfan syndrome have a 50 percent chance of passing the disorder to each of their children. In 25 percent of cases, a new gene defect occurs due to an unknown cause. Most people with the disorder have a tall and slender build, with disproportionately long arms and legs. They may have a breastbone that protrudes outward or dips inward as well as crowded teeth. Stretch marks are a common trait in people who have Marfan syndrome, usually appearing on the back, shoulders, thighs and abdomen.

Physical appearance

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Many of the signs of Marfan syndrome involve physical appearance, such as flat feet and a curved spine, but the most dangerous complications involve the heart and blood vessels. Marfan syndrome causes the walls of blood vessels to become weak and stretch. These blood vessel changes often affect the aorta, the major artery that carries blood from the heart to the rest of the body. When the walls of the aorta weaken, there is an increased risk of aortic aneurysm, dissection or rupture. People who have Marfan syndrome are also more likely to have problems with their heart valves, which may be malformed or overly elastic. When heart valves don’t work properly, the heart muscle often has to work harder to compensate, which can eventually lead to heart failure. Marfan syndrome can also cause breathing difficulties, either from defective connective tissue or from chest wall abnormalities, increasing the risk of emphysema and asthma.

No simple test

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Although it has been determined that Marfan syndrome is caused by a genetic defect, there is no simple blood test that can conclusively diagnose the disorder. Which is why a clinical evaluation is necessary to complete a thorough diagnosis. A cardiologist, an ophthalmologist, an orthopedist and a geneticist may all need to see the patient because the condition affects so many different parts of the body. A thorough history of symptoms and information about family members that may have had related problems are also necessary. Other tests, such as an X-ray, an electrocardiogram, also known as an ECG, and an echocardiogram will be used to evaluate changes in the heart and blood vessels, and detect heart rhythm problems. In some situations a blood test can be used to help diagnose Marfan. This blood test is highly specialized and looks for changes in FBN1, the gene that is responsible for most cases of Marfan.

A treatment plan

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Marfan syndrome requires a treatment plan that is individualized to the patient’s needs. Some people may not require any treatment, just regular follow-up appointments with their doctor. Others may need medications or surgery. The approach depends on the structures affected and the severity of the condition. Living with a genetic disorder can be difficult for both adults and children. Adults who receive a diagnosis late in life may wonder how the disease will affect their careers, their relationships and their sense of themselves. But Marfan syndrome can be even harder on young people because the often-inherent self-consciousness of childhood and adolescence may be exacerbated by the disease’s effect on appearance, academic performance and motor skills. In the long run, accurate information about the disease, good medical care and strong social support can help both children and adults cope with the condition.These programs were first broadcast the week of November 16, 2015.

T. Glenn Pait, M.D., of UAMS is the host of the program.