Download Marfan`s Syndrome

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Point mutation wikipedia , lookup

Medical genetics wikipedia , lookup

Pectus excavatum wikipedia , lookup

DiGeorge syndrome wikipedia , lookup

Down syndrome wikipedia , lookup

Turner syndrome wikipedia , lookup

Marfan’s Syndrome
By Emily Espinosa
Bernard Marfan, a french pediatrician, described the
disease that still bears his name at a meeting of the
Medical Society of Paris in 1896. He presented the
case of a 5-year-old girl named Gabrielle, who had
disproportionately long limbs.
In later studies, further anomalies were documented,
including arachnodactyly (long digits), cardiovascular
abnormalities, and dislocation of the ocular lens.
Marfan’s syndrome is a rare hereditary disorder that
causes connective tissue to be weaker than normal.
It is also known as arachnodactyly.
Connective tissue supports and protects various
other tissues, is a vital component of all organs in
the body, and provides strength and elasticity to
blood vessels.
For people with Marfan’s syndrome, weak
connective tissue causes problems of the skin, eyes,
blood vessels, and bones.
Marfan syndrome is caused by a defect (mutation) in
the gene, on chromosome 15, that tells the body
how to make fibrillin-1 -- a protein that is an
important part of connective tissue.
It is a gene mutation.
This defect results in an increase in a protein called
transforming growth factor beta, or TGFβ. The
increase of TGFβ causes problems in tissue
throughout the body, which create the different
Marfan syndrome features and cause medical
problems for people with Marfan syndrome.
People can inherit Marfan syndrome, meaning that they get the
mutation from a parent who has the disorder. This is the case
in about 3 out of 4 people with Marfan syndrome. However, the
defect is specific to each family, and not everyone experiences
the same characteristics of Marfan syndrome. This is called
variable expression.
Other people have a spontaneous mutation, meaning that they
are the first in their family to have Marfan syndrome.
People with Marfan syndrome have a 50-50 chance of passing
the mutation on each time they have a child.
Phenotypic Effects
People with the Marfan syndrome are often
tall and thin. They also may have slender,
tapering fingers, long arms and legs,
curvature of the spine, flexible joints, and
Chest may sink in (pectus excavatum) or
stick out (pectus carinatum).
Other Symptoms
Heart and Blood Vessels (Cardiovascular system)
Enlarged or bulging aorta, the main blood vessel that carries
blood from the heart (aortic dilation or aneurysm)
Separation of the layers of the aorta that can cause it to tear
(aortic dissection)
Eyes (Ocular system)
Severe nearsightedness (myopia)
Dislocated lens of the eye
Detached retina
Early glaucoma
Early cataracts
There is no specific laboratory test to diagnose Marfan syndrome. The
doctor and/or geneticist relies on observation and a complete medical
history, including
information about any family members who may have the disorder or
who had an early, unexplained heart-related death
a thorough physical examination, including an evaluation of the
skeletal frame for the ratio of arm/leg size to trunk size
an eye examination
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 there are 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.
There is no cure for Marfan syndrome. However there are treatments
available that depend on which systems are affected.
Bones and Joints (Skeletal System)
Annual evaluations are important to detect any changes in the spine or
breastbone (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
Eyes (Ocular)
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.
Treatment (continued)
Heart and Blood Vessels (Cardiovascular System)
Regular checkups and echocardiograms help the doctor evaluate the
size of the aorta and the way the heart is working. Those with heart
problems are encouraged to wear a medical alert bracelet and to go to
the emergency room if they experience chest, back or abdominal pain.
Some heart valve problems can be managed with drugs such as betablockers, which 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. Following heart surgery, extreme care
must be followed to prevent endocarditis (inflammation of the lining of
the heart cavity and valves). Dentists should be alerted to this risk;
they should provide protective medicines before they perform certain
dental work.