Marfan Syndrome

Marfan SyndromeMarfan syndrome is a genetic disorder that affects connective tissue. Connective tissue holds other tissues together throughout the body. Individuals with Marfan syndrome can have signs and symptoms involving the heart, blood vessels, bones and joints, and eyes. Sometimes the lungs and skin are also affected. Marfan syndrome does not affect intelligence. Signs and symptoms of Marfan syndrome can be mild or severe. They may be present at birth or become apparent in childhood or in adult life.

How common is Marfan syndrome?
Marfan syndrome affects about 1 in 5,000 Americans (1, 2). The disorder affects males and females of all races and ethnic groups. The condition is named for Dr. Antoine Marfan who, in 1896, described a 5-year-old girl with unusually long, slender fingers and limbs, and other skeletal abnormalities.

How are individuals with Marfan syndrome affected?
Affected individuals are tall, slender and loose-jointed. Arms, legs, fingers and toes often are unusually long. Some people with Marfan syndrome have low foot arches (flat feet), and others have high arches. Individuals with Marfan syndrome usually have long narrow faces, and their teeth are generally crowded.
Individuals with Marfan syndrome can have one or more of the following problems:
Heart and blood vessel problems: The most serious problem associated with Marfan syndrome is weakness of the wall of the aorta. The aorta is the body's largest artery, which carries oxygen-rich blood from the left side of the heart to the rest of the body. In Marfan syndrome, the wall of the aorta gradually weakens and stretches (aortic dilation) over time. Eventually, this can cause a tear (dissection) in the lining of the aorta. Blood can leak out through the tear into the aortic wall, sometimes resulting in a rupture, allowing blood to leak into the chest or abdomen. These complications, if not detected, can result in sudden death.
Abnormal heart valves: The heart's mitral valve tends to be floppy and billowing (mitral valve prolapse). Heart valves are tiny flaps or gates that keep the blood flowing in one direction through the heart. Differences in the mitral valve can allow blood to briefly flow backwards during a heartbeat (regurgitation). Sometimes this creates an abnormal sound that a health care provider may hear through a stethoscope. Mitral valve prolapse can sometimes be associated with irregular or rapid heartbeat and shortness of breath.
Skeletal abnormalities: Many individuals have a lateral (sideways) curvature of the spine (scoliosis). Sometimes there is a sharp forward curvature (kyphosis). Many individuals have deformities of their breastbone (sternum). These are called pectus deformities. Pectus deformities can sometimes protrude outward and/or inward. Sometimes the connective tissue which surrounds the spinal cord loosens and stretches out (dural ectasia) causing back pain.
Lung problems: Persons with Marfan syndrome are more prone than others to sudden collapse of their lungs (spontaneous pneumothorax). They also may develop respiratory problems and shortness of breath. Respiratory problems can worsen if the individual has severe skeletal abnormalities, which do not allow the chest to fully expand, or emphysema (a breathing disorder usually associated with smoking). Adults with Marfan syndrome are at increased risk of early emphysema, even if they don't smoke.
Eye problems: The lens of one or both eyes is off-center in about 60 percent of persons with Marfan syndrome (1, 2). This is called ectopia lentis. Most affected individuals also are nearsighted and have astigmatism (eyes cannot focus clearly). Individuals with Marfan syndrome are at increased risk of developing cataracts (clouding of the lens of the eye) and glaucoma (an increase of pressure in the eye) at an earlier age than individuals in the general population. Severe nearsightedness can lead to detachment of the retina (the light-sensing lining at the back of the eye). Retinal detachment and glaucoma can lead to vision loss.
Most individuals with Marfan syndrome have one or two of these problems. The severity of effects of Marfan syndrome varies greatly, even within the same family.

How is Marfan syndrome diagnosed?
An evaluation for Marfan syndrome generally includes:
A complete physical examination.
Eye examination by an ophthalmologist (eye doctor). The ophthalmologist uses eye drops to fully dilate the pupils of the eyes and examines them with a slit-lamp (a microscope with a light attached) to look for lens dislocation.
Heart tests, including an electrocardiogram (EKG), which measures electrical activity in the heart, and an echocardiogram. An echocardiogram is a special noninvasive ultrasound examination that lets doctors look for involvement of the heart and blood vessels, which often can't be determined by a physical examination.
Family history, in order to determine if there are other family members known or suspected to have Marfan syndrome, and/or who died early due to an unexplained heart disorder or an aneurysm (bulging of a blood vessel, such as the aorta, sometimes leading to rupture of the blood vessel).
Genetic testing of a blood sample to help confirm the diagnosis, in some cases.
Magnetic resonance imaging (MRI) of the lower spine to look for dural ectasia.

How is Marfan syndrome treated?
Advances in treatment have greatly improved the outlook for children and adults with Marfan syndrome. Today, the life expectancy of individuals with the disorder who receive proper treatment is about 70 years (1).
Most of the problems associated with Marfan syndrome can be managed effectively, as long as they are diagnosed early. The disorder usually is treated by a team of experienced physicians and health care professionals, overseen by a single doctor who knows all of its aspects.
The team of physicians should include a cardiologist (heart doctor). Affected individuals need to have serial (repeated periodically) echocardiograms to measure the dimensions of their aorta and the condition of their heart valves. These and other tests help the doctors determine whether or not treatment is needed, and when intervention should take place.
To help prevent or reduce heart problems, doctors often recommend treatment with high blood pressure medications called beta blockers. These medications reduce the strength and frequency of heartbeats, reducing stress on the wall of the aorta. Studies suggest that beta blockers may slow down the rate of dilation of the aorta and help prevent it from tearing (1, 2).
Strenuous exercise also can place stress on the aorta. Children and adults with Marfan syndrome should avoid strenuous exercise, including collision and contact sports (1, 2). Heavy lifting should be prohibited. With their doctor’s guidance, many can still participate in less vigorous activities, such as walking, playing golf, bicycle riding and swimming.
In spite of the use of medication, the aorta sometimes continues to dilate. Doctors will recommend surgery to repair the aorta before there is a danger of its tearing or dissecting. Doctors evaluate information from several sources when considering surgery and planning the timing of surgery.
For example, doctors use accurate measurements of the aorta to help determine the rate at which the aorta is dilating. Family history of others with aortic dilation/dissection also may influence the timing of surgery. Aortic repair also is considered when there is significant leaking of the aortic valve or worsening of the leak over time.
There are a few surgical options for repairing the aorta. In one operation, the surgeon replaces a section of the aorta with a synthetic tube (composite graft) and sometimes repairs or replaces the aortic valve. More recently, some individuals with Marfan syndrome have had what is called a valve-sparing procedure, in which the aortic valve is retained, and a portion of the aorta closest to the heart is replaced. Individuals with Marfan syndrome should have aortic surgery performed at a hospital where the surgeons are experienced with Marfan syndrome. The individuals should discuss the pros and cons of the various surgical options with their surgeon.
Early preventive surgery for aortic dilation is far safer than waiting until emergency surgery is needed. A 1999 study showed that with preventive surgery, the death rate was 1.5 percent vs. 12 percent for patients who had emergency surgery (3).
When necessary, other faulty heart valves also can be surgically repaired or replaced. After any valve replacement surgery, the individual must take anti-clotting medication for life, because blood tends to clot when it comes in contact with artificial valves.
Individuals with heart valve abnormalities, including most people with Marfan syndrome, and those who have had surgery to replace a heart valve or part of the aorta, are prone to heart valve infections. They must be treated with oral antibiotics to prevent infection of the valves before any procedure that may release bacteria into the blood stream. These procedures include dental work such as cleaning, filling and extractions, as well as other kinds of surgery. Individuals with Marfan syndrome should check with the cardiologist before dental procedures to see if additional treatment is recommended, such as a higher dose of antibiotics given by injection.
Sometimes individuals with Marfan syndrome who have had repair of the upper portion of the aorta have enlargement of other parts of their aortas. These individuals need to be followed with serial echocardiograms and a CT scan or MRI scan of the chest, abdomen and pelvis at least yearly. In some cases, surgical repair may be needed.
Children and adolescents with Marfan syndrome are monitored yearly for signs of scoliosis. Many develop mild scoliosis, which may not require treatment. In more severe or progressive cases, scoliosis can cause back pain and shortness of breath. In these cases, a brace or surgery is recommended. Bracing can sometimes halt the progression of scoliosis, although sometimes surgery is needed to correct the deformity. Pectus deformities also can interfere with breathing. Corrective surgery can be performed to alleviate these symptoms.
Children with Marfan syndrome should have a yearly eye examination by an ophthalmologist. Most eye problems, such as nearsightedness, can be corrected with glasses or contact lenses. Early treatment for cataracts and glaucoma usually can prevent or lessen vision problems. Detached retinas can be treated with lasers.

What causes Marfan syndrome?
Marfan syndrome is caused by mutations (changes) in one member of a pair of genes called the fibrillin genes. These genes are located on chromosome 15, one of the 23 pairs of human chromosomes. Normally, the fibrillin gene enables the body to produce fibrillin, a protein that is a crucial component of connective tissue. Fibrillin normally is an abundant component of the connective tissue found in the aorta, in the ligaments that hold the eye’s lenses in place, in bones and in the lung. The mutated fibrillin gene, in combination with the action of other genes, leads to the formation of faulty fibrillin.
The mutated fibrillin gene usually is inherited from one parent who has Marfan syndrome. The mutation is a “dominant” genetic trait. This means that each child of a parent with Marfan syndrome has a 50 percent chance of inheriting the mutation, and a 50 percent chance of not inheriting it. Only those children who inherit the mutation will develop the signs and symptoms of Marfan syndrome.
About 25 percent of cases of Marfan syndrome are sporadic. This means that they are caused by a new mutation that occurred by chance in one of the fibrillin genes in a sperm or egg cell of an unaffected parent (2). Parents who themselves do not have Marfan syndrome and do not have a family history of Marfan syndrome, but have an affected child, should meet with a genetic counselor to discuss their risks in another pregnancy.
As with other inherited disorders, Marfan syndrome cannot be “caught” from another person. Although it may be diagnosed at any age, the signs and symptoms of Marfan syndrome do not occur unless the person has the mutation.

Is pregnancy risky for women with Marfan syndrome?
There are several important issues for women with Marfan syndrome who are considering pregnancy. First, there is a 50 percent chance of having a child with Marfan syndrome with each pregnancy. Second, the stress of pregnancy may cause rapid enlargement of the aorta, especially if the aorta is significantly enlarged before pregnancy. The risk of dissection (tearing) of the aorta is low, but not zero, in women with Marfan syndrome who have a normal aortic size. The risk increases during pregnancy as the aorta enlarges.
Women with Marfan syndrome should consult their primary health care providers and their cardiologist before pregnancy to discuss whether pregnancy is safe for them. The cardiologist generally recommends an echocardiogram to determine the dimensions of the aorta.
During pregnancy, an affected woman should receive prenatal care from a high-risk obstetrician who has experience with Marfan syndrome. She should also see her cardiologist regularly. She will need to have an echocardiogram repeated in the first, second and third trimesters to monitor the size of her aorta. If the aorta measures less than 4 cm., there usually is a low risk of tears during pregnancy (1, 2). Women who are taking a beta-blocker generally can safely continue taking the medication throughout pregnancy. Those who have had a valve replaced usually are on an oral blood thinner called coumadin (warfarin). Because this drug increases the risk of birth defects, pregnant women are switched to another blood thinner called heparin, which is given by injection (usually two or three times a day), during pregnancy.
Women with Marfan syndrome do not appear to have an increased risk of miscarriage (1). One study suggests that they may be more likely than unaffected women to deliver prematurely (before 37 weeks of pregnancy) (4). Premature babies are at increased risk of health problems during the newborn period, as well as lasting disabilities.
Most women with Marfan syndrome can have a vaginal delivery. The doctor will take appropriate measures to lessen the stress of labor and delivery. However, if the woman has significant aortic dilation, a cesarean delivery generally is recommended.
A woman with Marfan syndrome should have a follow-up echocardiogram at one to two months after delivery to check the size of her aorta.

Can Marfan syndrome be prevented?
At present, there is no way to prevent Marfan syndrome. Early diagnosis can help prevent serious complications. Genetic counseling enables informed decisions about childbearing and provides up-to-date information about the genetic basis of Marfan syndrome and on genetic testing for this condition.