Causes - Marfan Syndrome - Causes

Marfan syndrome is a genetic condition caused by a mutation, or change, in one of your genes, called the fibrillin-1 (FBN1) gene. The FBN1 gene makes fibrillin-1, which is a protein that forms elastic fibers within connective tissue. Fibrillin-1 also affects levels of another protein that helps control how you grow.

Most people who have Marfan syndrome inherit 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 developing in the womb.