What is Marfan Syndrome?

Marfan syndrome (also called Marfan’s syndrome or Marfans syndrome) is a condition that affects the connective tissue. Connective tissue holds the body together and provides support to many structures throughout the body. In 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.

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What causes Marfan syndrome?

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 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 along the disorder to each of their children.

In 25 percent of cases, a new gene defect occurs due to an unknown cause. Marfan syndrome is also referred to as a “variable expression” genetic disorder, because not everyone with Marfan syndrome has the same symptoms to the same degree.

Marfan syndrome is present at birth. However, it may not be diagnosed until adolescence or young adulthood.

Who is affected by Marfan syndrome?

Marfan syndrome is fairly common, affecting 1 in 10,000 to 20,000 people. It has been found in people of all races and ethnic backgrounds.

What are the signs of Marfan syndrome?

Sometimes Marfan syndrome is so mild, few if any, symptoms occur. In most cases, the disease progresses with age and symptoms of Marfan syndrome become noticeable as changes in connective tissue occur.

Physical Appearance

People with Marfan syndrome are often very tall and thin. Their arms, legs, fingers and toes may seem out of proportion, too long for the rest of their body. Their spine may be curved and their breastbone (sternum) may either stick out or be indented. Their joints may be weak and easily become dislocated. Often, people with Marfan syndrome have a long, narrow face and the roof of the mouth may be higher than normal, causing the teeth to be crowded.

Marfan syndrome causes many changes to occur within the body structures, including dental and skeletal (bone) problems.

Dental and bone problems

Patients with Marfan syndrome may have a dental history of tooth extractions or palate expanders for a narrow palate. In addition, patients may have a history of bone problems such as flat feet, hernias and bone dislocations.

Other changes that occur with Marfan syndrome due to the abnormal connective tissue include changes in the eyes, heart and blood vessels, lungs and skin.

Eye problems

More than half of all people with Marfan syndrome have eye problems including nearsightedness (blurring of objects far away), lens subluxation (lens of the eye moves away from its typical position) or having a difference in the shape of the eye or other eye problems.

Changes in the heart and blood vessels

About 90 percent of people with Marfan syndrome develop changes in their heart and blood vessels.

Blood vessel changes: With Marfan syndrome, the walls of the blood vessels become weak and dilate (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 or stretch, there is an increased risk of aortic aneurysm, aortic dissection or rupture (bursting). All portions of the aorta can dilate or dissect. These conditions can result in a medical emergency and in some cases are life-threatening.

Patients also may have a history of intracranial bleeding or brain aneurysms, referred to as Berry aneurysms.

Heart valve problems: The heart’s valves, especially the mitral valve, can be affected by Marfan syndrome. The valve leaflets become floppy and do not close tightly, allowing blood to leak backwards across the valve (mitral valve prolapse, also called MVP). When MVP progresses, the valve leaks and the condition is called mitral valve regurgitation.

Mitral Valve Prolapse | Cleveland Clinic

Mitral valve prolapse Leaflets are stretched and flop back into the left atrium with each heart beat

Normal Mitral Valve | Cleveland Clinic

Normal mitral valve Leaflets close tightly

Mitral valve prolapse and regurgitation are associated with varying degrees of valve leakage. Mild valve leaks do not create extra work on the heart, but require routine follow-up. More significant valve leakages, as determined by your doctor, increase the workload on the heart and may cause symptoms of shortness of breath, feeling over-tired, or palpitations (fluttering in the chest). The abnormal flow may cause a heart murmur, which can be heard with a stethoscope. Over time, the heart may enlarge and heart failure may occur.

Cardiomyopathy: With Marfan syndrome, the heart muscle may enlarge and weaken over time, causing cardiomyopathy, even if the heart valves are not leaking. The condition may progress to heart failure.

Aortic root dilation: The aortic root is the area where the aorta meets the aortic valve. With Marfan syndrome, the aortic root may dilate or widen. This can cause the aortic valve to become stretched and leak.

Arrhythmia (abnormal heart rhythm): May occur in some patients with Marfan syndrome. Arrhythmia is often related to MVP.

Other signs of Marfan Syndrome

Lung changes: The changes in lung tissue that occur with Marfan syndrome increase the risk of asthma, emphysema (Chronic Obstructive Lung Disease, COPD), bronchitis, pneumonia and collapsed lung.

Skin changes: Decreased elasticity of the skin cause stretch marks to occur even without changes in weight.

Reviewed by a Cleveland Clinic medical professional.

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