The elastic fibers that make up the aorta in the heart, ligaments in the joints, and other supportive structures are affected most often. Without a strong network of connective tissue, support and stability of joints and tissues are compromised.

People with Marfan syndrome often have long limbs, long thin fingers, and are very tall.They are prone to abnormalities of the cardiovascular system. The heart valves and aorta are affected most often. The disorder may also affect many other structures and organs. This includes the lungs, eyes, sac around the spinal cord, and hard palate.

It was once thought that President Lincoln had Marfan Sydrome. More recent studies show this probably wasn't so.