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QUESTIONS
AND ANSWERS ABOUT MARFAN SYNDROME
This
fact sheet answers general questions about Marfan syndrome. It describes
the characteristics of the disorder, the diagnostic process, and
ways to manage symptoms. If you have additional questions after
reading this fact sheet, you may wish to discuss them with your
doctor.
What
Is Marfan Syndrome?
Marfan
syndrome is a heritable condition that affects the connective tissue.
The primary purpose of connective tissue is to hold the body together
and provide a framework for growth and development. In Marfan syndrome,
the connective tissue is defective and does not act as it should.
Because connective tissue is found throughout the body, Marfan syndrome
can affect many body systems, including the skeleton, eyes, heart
and blood vessels, nervous system, skin, and lungs.
Marfan
syndrome affects men, women, and children, and has been found among
people of all races and ethnic backgrounds. It is estimated that
at least 25,000 people in the United States have the disease.
What
Are the Characteristics of Marfan Syndrome?
Marfan
syndrome affects different people in different ways. Some people
have only mild symptoms, while others are more severely affected.
In most cases, the disease progresses as the person ages. The body
systems most often affected by Marfan syndrome are:
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Skeleton—People
with Marfan syndrome are typically very tall, slender, and loose
jointed. Their arms, legs, fingers, and toes may be disproportionately
long in relation to the rest of their body. A person with Marfan
syndrome often has a long, narrow face, and the roof of the
mouth may be arched, causing the teeth to be crowded. Other
skeletal abnormalities include a sternum (breastbone) that is
either protruding or indented, curvature of the spine (scoliosis),
and flat feet. The joints can also be very loose.
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Eyes—More
than half of all people with Marfan syndrome experience dislocation
of one or both lenses of the eye. The lens may be slightly higher
or lower than normal and may be shifted off to one side. The
dislocation may be minimal, or it may be pronounced and obvious.
Many people with Marfan syndrome are also nearsighted (myopic),
and some can develop early glaucoma (high pressure within the
eye) or cataracts (the eye’s lens loses its clearness).
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Heart
and blood vessels (cardiovascular system)—Most people with
Marfan syndrome have abnormalities associated with the heart
and blood vessels. The valve between the left chambers of the
heart is defective and may be large and floppy, resulting in
an abnormal valve motion when the heart beats. In some cases,
the valve may leak, creating a “heart murmur,” which a doctor
can hear with a stethoscope. Small leaks may not cause any symptoms,
but larger ones may cause shortness of breath, fatigue, and
palpitations (a very fast or irregular heart rate). Because
of faulty connective tissue, the wall of the aorta (the large
artery that carries blood from the heart to the rest of the
body) may be weakened and stretch, a process called aortic dilation.
Aortic dilation increases the risk that the aorta will tear
(aortic dissection) or rupture, causing serious heart problems
or sometimes even sudden death.
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Nervous
system—The brain and spinal cord are surrounded by fluid
contained by a membrane called the dura, which is composed of
connective tissue. As people with Marfan syndrome get older,
the dura often weakens and stretches, then begins to weigh on
the vertebrae in the lower spine and wear away the bone surrounding
the spinal cord. These changes may cause only mild discomfort
or may lead to radiated pain in the abdomen or legs. This is
called dural ectasia.
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Skin—Many
people with Marfan syndrome develop stretch marks on their skin,
even without any weight change. These stretch marks can occur
at any age and pose no health risk. However, people with Marfan
syndrome are also at increased risk for developing an abdominal
hernia: a weak part in the abdominal wall that can bulge and
contain part of the intestines.
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Lungs—Although
connective tissue abnormalities make the tiny air sacs within
the lungs less elastic, people with Marfan syndrome generally
do not experience noticeable problems with their lungs. If,
however, these tiny air sacs become stretched or swollen, the
risk of lung collapse may increase. Rarely, people with Marfan
syndrome may have sleep-related breathing disorders such as
snoring or sleep apnea (a sleep disorder characterized by brief
periods when breathing stops).
What
Causes Marfan Syndrome?
Marfan
syndrome is caused by a defect in the gene that determines the structure
of fibrillin, a protein that is an important part of connective
tissue. A person with Marfan syndrome is born with the disorder,
even though it may not be diagnosed until later in life. Although
everyone with Marfan syndrome has the same defective gene, not everyone
experiences the same symptoms to the same degree. This is called
“variable expression,” meaning that the defective gene expresses
itself in different ways in different people. Scientists do not
yet understand why variable expression occurs in people with Marfan
syndrome.
The
defective gene can be inherited: The child of a person who has Marfan
syndrome has a 50-percent chance of inheriting the disease. Sometimes,
a new gene defect (mutation) occurs during the formation of sperm
or egg cells, but two unaffected parents have only a 1 in 10,000
chance of having a child with Marfan syndrome.
How
Is Marfan Syndrome Diagnosed?
There
is no specific test to diagnose Marfan syndrome. The doctor and/or
geneticist (a doctor with special knowledge about inherited diseases)
relies on a complete medical history, including
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information
about any family members who may have the disorder,
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a
thorough physical examination, including an evaluation of the
skeletal frame for the ratio of arm/leg size to trunk size
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an
eye examination, including a “split lens” evaluation
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heart
tests such as an echocardiogram (a test that uses ultrasound
waves to examine the heart and aorta).
The
doctor may diagnose Marfan syndrome if the patient has a family
history of the disease and specific problems in at least two of
the body systems known to be affected. For a patient with no family
history of the disease, at least three body systems must be affected
before a diagnosis is made. Moreover, two of the systems must show
clear signs that are relatively specific for Marfan syndrome. In
some cases, a genetic analysis may be useful, but such analyses
are often time consuming and may not provide any additional helpful
information.
Family
members of a person diagnosed with Marfan syndrome should not assume
they are not affected if there is no known family history of the
disorder. They should also be evaluated for signs of Marfan syndrome.
What
Types of Doctors Treat Marfan Syndrome?
Because
a number of body systems may be affected, a person with Marfan syndrome
may be cared for by several different types of doctors. A general
practitioner or pediatrician may oversee routine health care and
refer the patient to specialists such as a cardiologist (a doctor
who specializes in heart disorders) or an ophthalmologist (a doctor
who specializes in eye disorders) as needed. Some people with Marfan
syndrome are also treated by a geneticist.
What
Treatment Options Are Available?
There
is no cure for Marfan syndrome. To develop one, scientists may have
to identify and change the specific gene responsible for the disorder
before birth. However, a range of treatment options can reduce symptoms.
The appropriate specialists will develop an individualized treatment
program; the approach the doctor uses depends on which systems have
been affected.
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Skeletal—Annual
evaluations are important to detect any changes in the spine
or sternum. This is particularly important in times of rapid
growth, such as adolescence. A serious deformity can not only
be disfiguring but can also prevent the heart and lungs from
functioning properly. In some cases, an orthopedic brace or
surgery may be recommended to limit damage and disfigurement.
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Eyes—Early,
regular eye examinations are key to catching and correcting
any vision problems associated with Marfan syndrome. In most
cases, eyeglasses or contact lenses can correct the problem,
although surgery may be necessary in some cases.
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Heart
and blood vessels—Regular checkups and echocardiograms help
the doctor evaluate the size of the aorta and the way the heart
is working. The earlier a potential problem is identified and
treated, the lower the risk of life-threatening complications.
Some heart valve problems can be managed with drugs such as
beta-blockers, which may help decrease stress on the aorta.
In other cases, surgery to replace a valve or repair the aorta
may be necessary. Surgery should be performed before the aorta
reaches a size that puts it at high risk for tear or rupture.
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Nervous
system—Although there is no way to prevent dural ectasia
from developing, medication may help minimize any associated
pain.
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Lungs—It
is especially important that people with Marfan syndrome not
smoke, as they are already at increased risk for lung damage.
Any problems with breathing during sleep should be assessed
by a doctor.
While
eating a balanced diet is important to maintaining a healthy lifestyle,
no vitamin or dietary supplement has been shown to help slow, cure,
or prevent Marfan syndrome.
What
Are Some of the Emotional and Psychological Effects of Marfan Syndrome?
Being
diagnosed and learning to live with a genetic disorder can cause
social, emotional, and financial stress. It often requires a great
deal of adjustment in outlook and lifestyle. A person who is an
adult when Marfan syndrome is diagnosed may feel angry or afraid.
There may also be concerns about passing the disorder to future
generations or about its physical, emotional, and financial implications.
The
parents of a child diagnosed with Marfan syndrome may feel sadness,
anger, and guilt. It is important for parents to know that nothing
that they did caused the fibrillin gene to mutate. Parents may be
concerned about the genetic implications for siblings or have questions
about the risk to future children. Some children with Marfan syndrome
are advised to restrict their activities. This may require a lifestyle
adjustment that may be hard for a child to understand or accept.
For
both children and adults, appropriate medical care, accurate information,
and social support are key to living with the disease. Genetic counseling
may also be helpful in understanding the disease and its potential
impact on future generations.
What
Is the Outlook for a Person With Marfan Syndrome?
While
Marfan syndrome is a lifelong disorder, the outlook has improved
in recent years. Early diagnosis and advances in medical technology
have improved the quality of life for people with Marfan syndrome
and lengthened their lifespan. In addition, early identification
of risk factors (such as aortic dilation) allows doctors to intervene
and prevent or delay complications. Advances being made by researchers
provide hope for the future. With early diagnosis and appropriate
management, the life expectancy for someone with Marfan syndrome
is similar to that of the average person.
What
Research Is Being Conducted To Help People With Marfan Syndrome?
Scientists
are approaching research on Marfan syndrome from a variety of perspectives.
One approach is to better understand what happens once the genetic
defect or mutation occurs. How does it change the way connective
tissue develops and functions in the body? Why are people with Marfan
syndrome affected differently? Scientists are searching for the
answers to these questions both by studying the genes themselves
and by studying large family groups affected by the disease. A newly
developed mouse model that carries a mutation in the fibrillin gene
may help scientists better understand the disease.
Other
scientists are focusing on ways to treat some of the complications
that arise in people with Marfan syndrome. Clinical studies are
being conducted to evaluate the usefulness of certain medications
in preventing problems with the aorta. Researchers are also working
to develop new surgical procedures to help improve the cardiac health
of people with Marfan syndrome.
Where
Can People Find Additional Information About Marfan Syndrome?
This
organization helps people who have Marfan syndrome and related connective
tissue disorders. It provides information and materials about the
disorder and about how to seek appropriate medical care.
This
clearinghouse, a public service sponsored by the National Institute
of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), provides
information on arthritis and musculoskeletal and skin diseases.
The clearinghouse distributes patient and professional education
materials and also refers people to other sources of information.
Acknowledgments
The
NIAMS gratefully acknowledges the assistance of Bernadette Tyree,
Ph.D., of the NIAMS; Harry C. Dietz, M.D., of The Johns Hopkins
University School of Medicine in Baltimore, MD; Joel Rosenbloom,
M.D., Ph.D., University of Pennsylvania, Philadelphia, Priscilla
Ciccariello, M.L.S., National Marfan Foundation and Coalition for
Heritable Disorders of Connective Tissue, Port Washington, NY; and
the National Marfan Foundation, Port Washington, NY in developing
and reviewing this fact sheet.
The
National Institute of Arthritis and Musculoskeletal and Skin Diseases
(NIAMS), a part of the National Institutes of Health (NIH), leads
the Federal medical research effort in arthritis and musculoskeletal
and skin diseases. The NIAMS supports research and research training
throughout the United States, as well as on the NIH campus in Bethesda,
MD, and disseminates health and research information. The National
Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse
(NAMSIC) is a public service sponsored by the NIAMS that provides
health information and information sources. Additional information
can be found on the NIAMS Web site at http://www.nih.gov/niams/.
April
1999
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