Marfan Syndrome

Marfan Syndrome Causes

How do you get Marfan syndrome?

Marfan syndrome is a condition you are born with. It is caused by a  mutations , or change, in a  genes , called the fibrillin-1 (FBN1) gene. The FBN1 gene makes fibrillin-1, which is a protein that forms elastic fibers within connective tissue to support your bones, muscles, and organs. Fibrillin-1 also affects levels of another protein that helps control how you grow.

Most people who have Marfan syndrome get it from their parents. Sometimes, the mutation that causes Marfan syndrome is not passed down from a parent but happens by chance while the unborn baby is growing.

How do parents pass on Marfan syndrome to their children?

When a parent has Marfan syndrome, there is a 50% chance that their child will have it. Every child receives two FBN1 genes, one from each parent. Children who get an FBN1 gene with a mutation from one parent will have Marfan syndrome even if the other parent passes on a normal FBN1 gene.

A flow chart of how Marfan syndrome is passed from parents to children


Can Marfan syndrome be prevented?

There is no way to prevent Marfan syndrome. Couples who are planning to have children and know that they are at risk of having a child with Marfan syndrome may want to meet with a genetic counselor.

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