Marfan Syndrome

Marfan syndrome is caused by a 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.

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. The mitral and aortic valves in the heart prevent "back flow" of blood leaving the heart. In people with Marfan syndrome, these valves are "leaky," allowing blood to flow backwards into the heart, causing:

• shortness of breath
• an irregular heart rhythm and pulse
• tiredness
• increased risk of heart failure (and even death) due to defects of the aortic valve

The aorta – the major vessel carrying blood from the heart to the rest of the body – is generally wider and more fragile. Continual widening can cause the aorta to become damaged and torn. An aneurysm (abnormal dilation or widening) of the aorta can develop at the outlet of the heart. Severe chest pain, sudden weakness, an unexplained fever, or tingling in the arms or legs should receive immediate and emergency medical treatment. These may be warning signs of an aortic rupture, which can be fatal.

Marfan syndrome can also affect the lungs, causing cysts to develop or a pneumothorax (air between the lung and chest wall) that can cause pain and shortness of breath. It can also cause widening of the sac that surrounds the spinal column in the low back causing headaches, back pain, or bowel and bladder problems. Some people with the syndrome also develop striae (stretch marks) on the shoulders and buttocks.

There's no specific lab test for Marfan syndrome. However, there are tests that can check for the defective gene or test for protein defects characteristic of this condition. People who have Marfan syndrome and go on to have children may want to consider gene testing so that complications of the syndrome can be detected and treated early. Because there are limits to genetic testing, testing needs to be done by someone who is familiar with Marfan syndrome and the testing limitations.

A doctor may suspect Marfan syndrome based on particular symptoms of its complications. The doctor will ask questions relating to a patient's family and medical history. A thorough physical examination will be supplemented with the following tests:

• chest X-rays, an echocardiogram (which gives a sound-wave "picture" of the heart), and an electrocardiogram (EKG) that provides information on how well the heart's functioning
• a complete skeletal examination to look for scoliosis
• a detailed eye examination called a slit lamp examination
• computed tomography (CT) and magnetic resonance imaging (MRI) scans

A diagnosis of Marfan syndrome is made when certain criteria, called Ghent criteria, are met. There are major criteria and minor criteria involving the parts of the body (e.g., bones, joints, eyes, heart, lungs) that are affected by Marfan syndrome.

When someone is diagnosed with Marfan syndrome, specialists such as cardiologists, orthopedic surgeons, and ophthalmologists are usually consulted.

In some cases, an ophthalmologist might even be the first one to detect signs of Marfan syndrome.

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.

Medications called angiotensin converting enzyme inhibitors (ACEIs e.g., perindopril) and angiotensin receptor blockers (ARBs e.g., losartan) are prescribed to reduce blood pressure without slowing the heart rate. These medications significantly slow down the weakening of the aorta and may prevent certain manifestations of Marfan syndrome, including aortic aneurysm.

The heart valves and aorta are monitored with regular echocardiograms. Valve problems and widening at the root of the aorta can be treated by surgically replacing a damaged section. Even though these are major surgeries, they're usually successful and lifesaving. Because of the enormous strain pregnancy puts on the heart, pregnant women with Marfan syndrome must be closely monitored.

Annual visits to an ophthalmologist allow Marfan-related eye complications to be quickly diagnosed. Eye glasses and contact lenses are usually enough to correct eye problems, but surgery may be also needed.

Curvature of the spine is treated using braces and physical therapy. For more extreme scoliosis, surgery is recommended to prevent progression and may even return the spine to its correct shape.

Antibiotics may be prescribed prior to dental procedures or other situations in which bacteria could enter the bloodstream. This is done to prevent infection in people with heart valve problems or those who have artificial heart valves.

Exercise should be limited to non-strenuous activities, such as walking, cycling, or jogging, which can be done at your own pace. High intensity competitive or contact sports aren't recommended.

Avoiding medications, such as decongestants, and foods containing caffeine is also recommended to prevent increases in blood pressure and to limit stretching of the connective tissue in the cardiovascular system.

It's important to remember that early diagnosis and treatment prevent far more serious complications from developing. Despite the high risks associated with heart and blood vessel problems, people with Marfan syndrome have an average life expectancy of about 70 years.

All material copyright MediResource Inc. 1996 – 2018. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Marfan-Syndrome