Genetic Testing for Marfan Syndrome
Genetic testing for Marfan syndrome may be useful in making a diagnosis; however, a genetic analysis is often time-consuming, and it may not yield any additional information. Because no specific laboratory test is used to make a diagnosis, doctors must rely on the patient's medical history, physical exam, and certain test results.
Are There Genetic Tests for Marfan Syndrome?
There is no specific laboratory test that is used to make a Marfan syndrome diagnosis. To make a diagnosis, your doctor or geneticist (a doctor with special knowledge about inherited diseases) will rely on:
- A complete medical history
- A physical exam
- Certain tests.
Genetic testing may also be useful in making a diagnosis of Marfan syndrome.
How Does Genetic Testing for Marfan Syndrome Work?
A genetic analysis may be helpful in making a Marfan syndrome diagnosis. However, a genetic analysis is often time-consuming, and it may not provide any additional information.
Family members of patients with Marfan syndrome should not assume that they have the disease if there is no knowledge that the disorder existed in previous generations. After a clinical diagnosis of a family member has been made, a genetic study might identify the specific mutation to determine if other family members are affected.
Understanding the Defect
Marfan syndrome is caused by a defect (mutation) in the fibrillin-1 (FBN1) gene. The FBN1 gene produces a protein that is essential for formatting the elastic fibers found in connective tissue.
Although a Marfan syndrome diagnosis may not be made until later in life, people are born with Marfan syndrome. People with Marfan syndrome have a defect in the same gene. However, the defect is specific to each family and not everyone experiences the same characteristics of Marfan syndrome. This is called variable expression. Marfan research scientists do not yet understand why variable expression occurs in people with this disorder.