Marfan Syndrome Marfan Syndrome
National Human Genome Research Center
WHAT IS MARFAN SYNDROME? Marfan syndrome is one of the most common inherited disorders of connective tissue. It is an autosomal dominant condition occurring once in every 10,000 to 20,000 individuals. There is a wide variability in clinical symptoms in Marfan syndrome with the most notable occurring in eye, skeleton, connective tissue and cardiovascular systems. Marfan syndrome is caused by mutations in the FBN1 gene. FBN1 mutations are associated with a broad continuum of physical features ranging from isolated features of Marfan syndrome to a severe and rapidly progressive form in newborns. ———————————————— WHAT ARE THE SYMPTOMS OF MARFAN? The most common symptom of Marfan syndrome is myopia (nearsightedness from the increased curve of the retina due to connective tissue changes in the globe of the eye). About 60 percent of individuals who have Marfan syndrome have lens displacement from the center of the pupil (ectopia lentis). Individuals who have Marfan syndrome also have an increased risk for retinal detachment, glaucoma and early cataract formation. Other common symptoms of Marfan syndrome involve the skeleton and connective tissue systems. These include bone overgrowth and loose joints (joint laxity). Individuals who have Marfan syndrome have long thin arms and legs (dolichostenomelia). Overgrowth of the ribs can cause the chest bone (sternum) to bend inward (pectus excavatum or funnel chest) or push outward (pectus carinatum or pigeon breast). Curvature of the spine (scoliosis) is another common skeletal symptom that can be mild or severe and progressively worsen with age. Scoliosis shortens the trunk also contributes to the arms and legs appearing too long. Cardiovascular malformations are the most life threatening symptom of Marfan syndrome. They include dilated aorta just as it leaves the heart (at the level of the sinuses of Valsalva), mitral valve prolapse, tricuspid valve prolapse, enlargement of the proximal pulmonary artery, and a high risk for aortic tear and rupture(aortic dissection). ————————————————- HOW IS MARFAN SYNDROME DIAGNOSED? The diagnosis of Marfan syndrome is a clinical diagnosis that is based on family history and the presence of characteristic clinical findings in ocular, skeletal and cardiovascular systems. There are four major clinical diagnostic features: Dilatation or dissection of the aorta at the level of the sinuses of Valsava. Ectopia lentis (dislocated lens of the eye). Lumbosacral dural ectasia determined by CT scan or magnetic resonance imaging (MRI). Four of the eight typical skeletal features.