Marfan syndrome is a disorder of connective tissue. This is the tissue that strengthens the body's structures.
Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and skin.
Marfan syndrome is caused by defects in a gene called fibrillin-1. Fibrillin-1 plays an important role as the building block for connective tissue in the body.
The gene defect also causes the long bones of the body to grow too much. People with this syndrome have tall height and long arms and legs. How this overgrowth happens is not well understood.
Other areas of the body that are affected include:
Lung tissue (there may be a pneumothorax, in which air can escape from the lung into the chest cavity and collapse the lung)
The aorta, the main blood vessel that takes blood from the heart to the body may stretch or become weak (called aortic dilation or aortic aneurysm)
The eyes, causing cataracts and other problems (such as a dislocation of the lenses)
Tissue covering the spinal cord
In most cases, Marfan syndrome is passed down through families (inherited). However, up to 30% of patients have no family history, which is called "sporadic." In sporadic cases, the syndrome is believed to be caused by a new gene change.
People with Marfan syndrome are very often tall with long, thin arms and legs and spider-like fingers (called arachnodactyly). The length of the arms is greater than height when arms are stretched out.
An echocardiogram or another test should be done every year to look at the base of the aorta and possibly the heart valves.
Vision problems should be treated when possible.
Monitor for scoliosis, especially during the teenage years.
Medicine to slow the heart rate may help prevent stress on the aorta. To avoid injuring the aorta, people with the condition should avoid participating in contact sports. Some people may need surgery to replace the aortic root and valve.
People with Marfan syndrome who have heart valve conditions may need to take antibiotics before dental procedures to prevent endocarditis (infection of the valves). Pregnant women with Marfan syndrome must be monitored very closely because of the increased stress on the heart and aorta.
Doyle J, Dietz III H. Marfan syndrome. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 693.
Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.