Marfan Syndrome

Marfan syndrome is a genetic connective tissue disorder affecting approximately 1 in 5,000 people. Individuals with Marfan syndrome can have a variety of different features in many different parts of the body including the heart, blood vessels, bones, joints, eyes, lungs and skin. Since Marfan syndrome can affect different people in so many different ways, the making a diagnosis can be challenging. Diagnosing Marfan syndrome requires consulting specialists familiar with the condition. Evaluation usually involves an echocardiogram (ultrasound of the heart), specific eye examination, a genetic consultation and often genetic testing.

Treatment for Marfan syndrome depends on what features a person has but may involves taking a medication to protect the heart and blood vessels, surgery for more serious heart problems associated with the condition, corrective lenses or surgery for eye problems and orthopedic care for problems with the bones and joints. With appropriate medical care, individuals with Marfan syndrome can live long, healthy lives.


Marfan syndrome in caused by abnormalities in the protein fibrillin-1; a key component of connective tissue. Alterations (mutations) in the FBN1 gene cause fibrillin-1 abnormalities and the different features and medical problems associated with Marfan syndrome. Even though Marfan syndrome is highly variable, everyone with an FBN1 gene mutation develops some features of Marfan syndrome.

Marfan syndrome is inherited in an autosomal dominant pattern. This means that individuals with Marfan have a 50% chance to pass the gene mutation to each of their children. Most of the time the gene mutation is inherited from a parent and other members of the family have the condition. However, about 25% of individuals with Marfan are the first member of their family to have the condition because their gene mutation occurred spontaneously very early in their development. Even if there is no family history, the children of anyone with Marfan syndrome have a 50% chance to have the condition.

Genetic testing can be done to confirm the diagnosis and so other family members can have genetic testing to determine if they have the condition.

Family members

Since Marfan syndrome is a genetic condition, the family members of someone who has the condition may be at risk for related medical problems. Close relatives (parents, siblings, and children) of someone with Marfan should be evaluated for the condition by consulting a geneticist or through genetic testing if the gene mutation associated with the condition in the family has been found.

Medical geneticist and genetic counselors are experts in genetic syndromes such as Marfan. Individuals can be evaluated in the Marfan clinic at UCSF by calling (415) 353-2554. Genetics providers at other hospitals can be located by searching on this website.

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