Marfan’s Syndrome By Emily Espinosa

History 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 conditions were documented, including arachnodactyly (long digits), cardiovascular abnormalities, and dislocation of the ocular lens.

Background 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.

Causes Marfan syndrome is caused by a defect (mutation) in the FBN1 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. Some researchers believe that a small percentage of Marfan syndrome cases are caused by mutations in the TGFBR2 gene. Other researchers believe that TGFBR2 mutations cause a disorder that may have some Marfan-like features but is not 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

Diagnosis 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.

Treatment 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 recommended. 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. Some heart valve problems can be managed with drugs such as beta-blockers, 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.

Bibliography http://www.marfan.org/marfan/ http://www.americanheart.org/presenter.jhtml?identifier=4672 http://www.medicinenet.com/marfan_syndrome/article.htm http://journals.tubitak.gov.tr/medical/issues/sag-99-29-2/sag-29-2-24-98135.pdf http://genetics.emedtv.com/genetics-articles-a-to-z-page-2.html