The molecular defect does not appear to interfere with fertility, so the disease is readily passed down in families. In about 25 percent of cases there is no family history, and, presumably, the mutation in the fibrillin gene occurred in that person. The variation in the severity of the different parts of this illness make it difficult to know how it will progress in any individual. If chest deformities or scoliosis are not present, the skeletal changes are usually not a problem. The eye problems can be more debilitating, with extreme nearsightedness often present along with the lens dislocation.
Retinal detachments can occur.
The most life-threatening problem is the aortic aneurysm that may develop. These can expand and rupture, particularly if high blood pressure is also present. A ruptured aneurysm is rapidly fatal if not immediately treated, so most doctors will schedule periodic echocardiograms to monitor the aorta, and may prescribe drugs to keep the blood pressure low. If the aorta is expanding, or reaches a critical size, then surgical replacement is recommended. Someone with Marfan's who avoids problems with his or her aorta can live to a ripe old age.