Marfan syndrome is a genetic disorder that affects the body's connective tissue – the tissue that makes up our tendons, ligaments, joints, and muscles, including the heart, blood vessels, and eyes.

CAUSES

Marfan syndrome is caused by an autosomal dominant gene. This means a person only needs to have one copy of the defective gene to have the disease. The abnormal gene is known as FBN1, located on chromosome 15 (in some cases, a second gene on chromosome 5 is also involved). Only one-quarter of cases are caused by "new" or spontaneous mutations. The majority of people inherit the gene from one of their parents. People with Marfan syndrome have a 50% chance of passing it on to each of their children.

The mutated gene affects the ability to produce fibrillin, a building block of connective tissue. This tough, elastic material connects parts of the body and provides structural support for many body tissues. With Marfan syndrome, the weakened connective tissue takes a toll on cartilage, tendons, ligaments, bones, heart valves, and large blood vessels.

SYMPTOMS AND COMPLICATIONS

Marfan syndrome causes various complications related to connective tissue. However, not all people have all of the complications. One person might have no identifiable problems, while another may have all the complications listed below. When complications occur, the severity of symptoms can vary widely.

Skeletal abnormalities commonly occur with Marfan syndrome. People are usually very tall and slender, with arms, legs, and fingers disproportionately long relative to the rest of the body. In some cases, the chest wall might "cave in" or protrude in front. Some people also have scoliosis, curvature of the spine.

Vision problems are common. Many children become nearsighted early in their lives. The lens of the eye (held in place by weakened ligaments) is prone to dislocation. The results are usually vision problems, and surgery may be necessary. People with Marfan syndrome are also at greater risk of the retina detaching – requiring emergency surgery – or of getting cataracts and glaucoma.

The most serious problems involve the heart and blood vessels. 

TREATMENT AND PREVENTION

Since symptoms vary from one person to the next, the different complications encountered with Marfan syndrome must be treated individually. Once the disorder has been diagnosed, a doctor – preferably somebody with experience treating Marfan syndrome – will keep close tabs on the bodily systems that are vulnerable to developing problems.

Medications called beta-blockers (e.g., propranolol*, atenolol) are prescribed to slow the heart rate and reduce the force of contractions, thus lowering the strain on the heart and reducing the risk of widening and tearing of the aorta. Angiotensin II receptor blockers (eg, losartan) may be taken with beta-blockers to help slow the rate of aortic root enlargement.