Marfan's Syndrome is most often a hereditary disease. The gene which causes Marfan's Syndrome is a dominant gene, yet, Marfan's Syndrome is a very rare disease. It is estimated that 5 out of every 100,000 people have Marfan's Syndrome. If one parent has Marfan's Syndrome, there is a 50% his/her children will have it as well. In some cases, Marfan's Syndrome is not always hereditary. Nearly 15% of the people who have it did not get it from a family member. In these people, it occurs because one of their new genes mutates. If there is a trait of "tallness" in a family, it does not necessarily mean the Marfan's Syndrome is the cause of it.

Marfan's Syndrome causes a defect to the development of the some of the connective tissue in the body. Connective tissue holds certain tissues and organs in place. If someone has Marfan's Syndrome, the effect is very easy to see. The person who has it will have very long legs and long arms that are often longer than the body. The fingers, feet, and toes, in some cases, are very long and bony. Another trait is that the person's chest has funnel-shaped deformities. Sometimes, the lenses of the eyes are not in the normal position and this can cause vision problems. Sometimes, the person will acquire heart and major blood vessel problems which normally will cause death to the patient. Most Marfan patients will most likely not reach the age of 50. Doctors have not been able to find a cure for Marfan's Syndrome, but if the problem is diagnosed early, and the correct procedures are taken, the patient's condition will often be improved.