Marfan syndrome is a rare hereditary disorder of connective tissue, resulting in abnormalities of the eyes, bones, heart, blood vessels, lungs, and central nervous system.
Marfan syndrome is caused by mutations in the gene that codes for a protein called fibrillin. Fibrillin helps connective tissue maintain its strength. If the fibrillin gene is mutated, some fibers and other parts of connective tissue undergo changes that ultimately weaken the tissue. The weakening affects bones and joints as well as internal structures, such as the heart, blood vessels, eyes, lungs, and central nervous system (the brain and spinal cord). Weakened tissues stretch, distort, and can even tear. For example, the aorta (the main artery of the body) may weaken, bulge, or tear. Weak tissues in a heart valve can cause the valve to leak. Connective tissues that join structures may weaken or break, separating formerly attached structures. For example, the eye's lens or retina may separate from its normal attachments.
Symptoms can range from mild to severe. Many people with Marfan syndrome never notice symptoms. In some people, symptoms may not become apparent until adulthood. People with Marfan syndrome are taller than expected for their age and family. Their arm span (the distance between fingertips when the arms are outstretched) is greater than their height. Their fingers are long and thin. Often, the breastbone (sternum) is deformed and pushed outward or inward. The joints may be very flexible. Flat feet, a deformity of the knee joint that causes the knee to bend backward, and a humpback with an abnormal curve of the spine (kyphoscoliosis) are common, as are hernias. Usually, the person has little fat under the skin. The roof of the mouth is often high.
The most dangerous complications develop in the heart and lungs. Weakness may develop in the connective tissue of the wall of the aorta. The weakened wall may result in blood seeping between the inner layers of the aorta's wall (aortic dissection—see Aortic Dissection), which causes a tear, or in a bulge (aneurysm—see Aneurysms) that can rupture. These problems sometimes develop before a child is 10 years old.
Pregnancy increases the risk of dissection. Caesarean delivery is often recommended to minimize the risk.
If the aorta gradually widens or dilates, the aortic valve, which leads from the heart into the aorta, may begin to leak (called aortic regurgitation). Widening of the aorta occurs in 50% of children and in 60 to 80% of adults. The mitral valve, which is located between the left atrium and ventricle, may leak (regurgitation) or bulge backward into the left atrium (prolapse—see Mitral Valve Prolapse (MVP)).
These heart valve abnormalities can impair the heart's ability to pump blood. Abnormal heart valves can also develop serious infections (infective endocarditis).
Air-filled sacs (cysts) may develop in the lungs. The cysts may rupture, bringing air into the space that surrounds the lungs (pneumothorax—see Pneumothorax). These disorders can cause pain and shortness of breath.
The lens of one or both eyes may be displaced (dislocated). People are very nearsighted. The light-sensitive area at the back of the eye (retina) may detach from the rest of the eye. Displacement of the lens and detachment of the retina may cause permanent loss of vision.
Spinal cord problems:
The sac that surrounds the spinal cord may widen (called dural ectasia). Dural ectasia is common and most frequently occurs in the lower portions of the spine. It may cause headache, lower back pain, or other neurologic problems such as bowel or bladder weakness.
Doctors may suspect the diagnosis if an unusually tall, thin person has any of the characteristic symptoms or if Marfan syndrome has been recognized in other family members (first-degree relatives such as the father, mother, or a sibling). Doctors also base the diagnosis on specific criteria regarding the extent to which certain organ systems, such as the heart, eyes, and bones, are affected.
Doctors monitor for complications that can cause serious symptoms. Echocardiography is used to evaluate the heart and aorta and is usually repeated yearly (see Echocardiography and Other Ultrasound Procedures). MRI can also be done to evaluate heart and brain problems. X-rays of the hand, spine, pelvis, chest, foot, and skull are done yearly to check for abnormalities. The eyes are usually examined yearly. Echocardiography and eye examinations are also done whenever symptoms develop.
Years ago, most people with Marfan syndrome died in their 40s. Today, people who have Marfan syndrome have nearly the same life expectancy as people who do not have this condition. Prevention of aortic dissection and rupture probably explains why the life span has been lengthened. However, life expectancy is still reduced for the average person mostly because of the heart and blood vessel complications.
There is no cure for Marfan syndrome or any way to correct the abnormalities in the connective tissue.
Treatment is aimed at preventing and fixing abnormalities before dangerous complications develop. Beta-blockers (such as atenolol and propranolol) are given to make blood flow more gently through the aorta. If the aorta has widened or developed an aneurysm, the affected section can be repaired or replaced surgically. Severe valve regurgitation is also surgically repaired. Pregnant women are at especially high risk of complications with their aorta, so repair of the aorta before conception should be discussed.
A displaced lens or retina can usually be reattached surgically.
A brace is used to treat abnormal curving of the spine for as long as possible. However, some children need a surgical procedure to correct the curve.
People should receive genetic counseling. People and their families may obtain additional information from the National Marfan Foundation.
Last full review/revision December 2014 by David D. Sherry, MD; Frank Pessler, MD, PhD