Genetics Home > Marfan Syndrome
Marfan syndrome is an inheritable condition in which the body's connective tissues are defective. Connective tissues hold the body together and provide a framework for growth and development. Therefore, this condition can affect many body systems, including the skeleton, eyes, and lungs. In the United States, it affects 1 in 5,000 to 1 in 10,000 people.
Marfan syndrome is an inheritable condition that affects the body's connective tissues. The primary purpose of connective tissue is to hold the body together and to provide a framework for growth and development. In Marfan syndrome, the connective tissue is defective.
Connective tissue is found throughout the body. Therefore, Marfan syndrome can affect many body systems, which include the:
- Heart and blood vessels
- Nervous system
In the United States, Marfan syndrome affects 1 in 5,000 to 1 in 10,000 people. It affects both males and females and occurs in all ethnic groups.
Genes and Inheritance
Marfan syndrome is caused by mutations in the fibrillin-1 (FBN1) gene. The FBN1 gene produces a protein that is essential for formatting the elastic fibers found in connective tissue. A mutation can decrease the amount and quality of FBN1 that is deposited in connective tissue, which can lead to a weakened structural support.
Marfan syndrome is inherited in an autosomal dominant pattern, which means that one copy of the altered gene is sufficient to cause the condition. Statistics related to the causes of this syndrome include:
- About 75 percent of people with Marfan syndrome inherit the mutation from one affected parent.
- About 25 percent of Marfan syndrome cases result from a new mutation in the gene. These cases occur in people with no history of the disorder in their family.