Hereditary Musculoskeletal Disorders: Marfan's Syndrome

Description

Marfan syndrome is a heritable condition caused by a defect in the gene that determines the structure of fibrillin , a protein that is an important part of connective tissue . The primary purpose of connective tissue is to hold the body together and provide a framework for growth and development. In Marfan syndrome, the connective tissue is defective and does not act as it should. Because connective tissue is found throughout the body, Marfan syndrome can affect many body systems, including the skeleton, eyes, heart and blood vessels, nervous system, skin, and lungs. Marfan syndrome affects men, women, and children, and has been found among people of all races and ethnic backgrounds. It is estimated that at least 25,000 people in the United States have the disease.

Symptoms and Signs

Marfan syndrome affects different people in different ways. Some people have only mild symptoms, while others are more severely affected. In most cases, the disease progresses as the person ages. The body systems most often affected by Marfan syndrome are:

• Skeleton. People with Marfan syndrome are typically very tall, slender, and loose jointed and often have a long, narrow face, also, the roof of the mouth may be arched, causing the teeth to be crowded. Their arms, legs, fingers, and toes may be disproportionately long in relation to the rest of their body. Other skeletal abnormalities include a sternum (breastbone) that is either protruding or indented, curvature of the spine ( scoliosis ), and flat feet .
• Eyes . More than half of all people with Marfan syndrome experience some dislocation of one or both lenses of the eye. Many people with Marfan syndrome are also nearsighted ( myopic ), and some can develop early glaucoma (high pressure within the eye) or cataracts (the eye’s lens loses its clearness).
• Heart and blood vessels (cardiovascular system. Most people with Marfan syndrome have abnormalities associated with the heart and blood vessels. These may include: an abnormal valve motion when the heart beats; leaking of the valve, creating a “heart murmur”; the wall of the aorta (the large artery that carries blood from the heart to the rest of the body) may be weakened and stretch, ( aortic dilation ). Aortic dilation increases the risk that the aorta will tear ( aortic dissection ) or rupture, causing serious heart problems or sometimes even sudden death.
• Nervous system . The brain and spinal cord are surrounded by fluid contained by a membrane called the dura, which is composed of connective tissue. As people with Marfan syndrome get older, the dura often weakens and stretches, then begins to weigh on the vertebrae in the lower spine and wear away the bone surrounding the spinal cord. These changes may cause only mild discomfort or may lead to radiated pain in the abdomen or legs. This is called dural ectasia .
• Skin . Many people with Marfan syndrome develop stretch marks on their skin, even without any weight change. These stretch marks can occur at any age and pose no health risk. However, people with Marfan syndrome are also at increased risk for developing an abdominal hernia : a weak part in the abdominal wall that can bulge and contain part of the intestines.
• Lungs . If the tiny air sacs within the lungs become stretched or swollen, the risk of lung collapse may increase. Rarely, people with Marfan syndrome may have sleep-related breathing disorders such as snoring or sleep apnea .

Diagnosis and Treatment

There is no specific test to diagnose Marfan syndrome. The doctor may diagnose Marfan syndrome if the patient has a family history of the disease and specific problems in at least two of the body systems known to be affected. For a patient with no family history of the disease, at least three body systems must be affected before a diagnosis is made. In some cases, a genetic analysis may be useful.

There is no cure for Marfan syndrome. However, a range of treatment options can reduce symptoms. The specific treatment used depends on the system affected:

• Skeletal . Annual evaluations are important to detect any changes in the spine or sternum. This is particularly important in times of rapid growth, such as adolescence . In some cases, an orthopaedic brace or surgery may be recommended to limit damage and disfigurement.
• Eyes . Early, regular eye examinations are key to catching and correcting any vision problems associated with Marfan syndrome. In most cases, eyeglasses or contact lenses can correct the problem, although surgery may be necessary in some cases.
• Heart and blood vessels . Regular check-ups and echocardiograms help the doctor evaluate the size of the aorta and the way the heart is working. The earlier a potential problem is identified and treated, the lower the risk of life-threatening complications. Some heart valve problems can be managed with drugs such as beta-blockers, which may help decrease stress on the aorta. In other cases, surgery to replace a valve or repair the aorta may be necessary. Surgery should be performed before the aorta reaches a size that puts it at high risk for tear or rupture.
• Nervous system . Although there is no way to prevent dural ectasia from developing, medication may help minimise any associated pain.
• Lungs . It is especially important that people with Marfan syndrome not smoke, as they are already at increased risk for lung damage. Any problems with breathing during sleep should be assessed by a doctor.

While Marfan syndrome is a lifelong disorder, the outlook has improved in recent years. Early diagnosis and advances in medical technology have improved the quality of life for people with Marfan syndrome and lengthened their lifespan. In addition, early identification of risk factors (such as aortic dilation) allows doctors to intervene and prevent or delay complications.

For further, more detailed information on this topic, please refer to the reference source for this page.

The information in this page is presented in summarised form and has been taken from the following source(s):
1. National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health: http://www.niams.nih.gov/