Marfan syndrome is a rare disorder. It causes a defect in the body’s connective tissue. Connective tissue supports and connects many of the body's structures. As a result, Marfan syndrome affects many organ systems, including:

  • Skeleton, especially the joints
  • Heart and the aorta, which is the artery that leads from the heart
  • Lungs
  • Eyes

Marfan syndrome is caused by a defect in a gene. The gene controls a protein needed to build connective tissue.

In almost all cases, the defective gene is passed from a parent. In rare cases, the defect can be caused by a mutation.