Marfan syndrome is a genetic condition affecting the body’s connective tissues. Connective tissue forms the body’s structure and holds the body together, setting the foundation for growth and development. It affects approximately one in 5,000 Americans. Although a gene for this condition has been identified, making a diagnosis can be very involved and requires the collaboration of many specialists.
The genetic mutation that causes this syndrome affects the way a specific protein, called fibrillin, is built in the body. Fibrillin is a key element of our connective tissue. Because it is caused by a variable expression gene, the syndrome can be manifested in different ways by members of the same family carrying the same mutation. Often, different members of the family can carry different mutations of the Marfan-causing gene. The odds are high for people with this condition to pass it on to their children, about 50%. Those without the gene have about a 1 in 10,000 chance of conceiving a child with a spontaneously mutated gene that causes Marfan.
Diagnosis requires the collaboration of an assortment of doctors and specialists, including orthopedists, ophthalmologists, cardiologists and geneticists. The doctors evaluate the patient's family history, conduct a physical exam to evaluate the skeletal structure and perform an echocardiogram (EKG) to evaluate the heart valves and the aorta. An eye exam, which includes pupil dilation, is also performed.
There are two basic criteria to diagnose Marfan. If there is a family history of the condition, at least two of the patient's bodily systems must exhibit symptoms. If the disease is not present in one's family history, then at least three bodily systems must display symptoms. While a genetic test can be performed, it is expensive and used as a last resort.
Symptoms of Marfan syndrome are manifested throughout several systems of the body, including:
- Skeletal: Those with this syndrome are taller than the average person and have a slim build, along with loose joints and flat feet. Limbs, fingers and toes are longer and out of proportion with the rest of the body. Other symptoms include a long, slender face and a highly arched mouth with crowded teeth. Scoliosis may be present, along with a concave or projecting breastbone.
- Skin: Stretch marks may mysteriously appear on the skin with no apparent cause.
- Eyes: People with this condition may have the lenses of their eyes dislocated or abnormally placed. Other possible optical symptoms include glaucoma, cataracts, detachment of the retinas and myopia.
- Nervous System: The dura, a membrane made of connective tissue, contains the important fluid that cushions and protects the brain and spinal cord. Because connective tissue is abnormal in a patient with this condition, the dura stretches and causes undue stress and wear on the spinal cord. This may cause pain and discomfort in those affected.
- Cardiovascular System: Complications to the heart and blood vessels are the most common cause of death in patients with Marfan syndrome. Valves can become stretched and flaccid, which interferes with normal valve motion. This may cause a heart murmur or small or large leaks. As a result, a person with this syndrome may experience fatigue, heart palpitations and shortness of breath. Aortic dilation, which is the stretching and weakening of the aorta, may result in the dissection of the aorta, which can lead to death.
- Lungs: Due to abnormalities associated with the skeletal and spinal structure, such as scoliosis, those with Marfan are predisposed to sudden lung collapse and an early onset type of emphysema. Problems with the lungs are also related to the fact that fibrillin is associated with the lungs. This condition may also cause heavy snoring, as well as sleep apnea.
Although there is currently no cure for Marfan syndrome, doctors treat the symptoms as they relate to each body system. As with most diseases, early diagnosis is important, especially as it relates to the potential complications of the cardiovascular system. Genetic counseling is also available for parents who have to choose whether they want to take the risk of passing it on to future children.