People at highest risk for Marfan syndrome are those who have a family history of the condition. If you have Marfan syndrome, each of your children has a 50 percent chance of having the altered gene that causes the condition.
Marfan syndrome affects about 1 out of every 5,000 people in the United States. Men, women, children, and people of all races can have the condition.
This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.