What is Marfan Syndrome?

Marfan syndrome is a genetic disorder of the connective tissue which affects many organ systems throughout the body, including the skeleton, heart, eyes, lungs, blood vessels and nervous system.  The condition occurs in approximately 1 out of 3,000 people and affects both males and females of any race or ethnic group. 

The expression of Marfan syndrome is VARIABLE and may be mild or quite severe.  Characteristic features may also differ from one diagnosed individual to the next.  Several specific features must be present to confirm a diagnosis.

Symptoms of the Marfan syndrome include:

• Family history
• Enlarged Aorta, Mitral  valve prolapse
• Visual problems – nearsightedness (myopia) or dislocation of the ocular lens
• Usually tall lean stature with disproportionately long arms and legs
• Excessively long thing fingers – arachnodactyl (spiderlike)
• Long narrow facial features
• Narrow, highly arched palate and proportionally small jaw
• Scoliosis (sideways curve of the spine)
• Extremely loose and flexible joints often prone to dislocation
• Sunken or protruding chest
• Pneumothorax (spontaneious collapse of the lung)
• Dural ectasia (enlargement of the dura), primarily in the lower portion of the spine which can wear down the bones of the vertebral column
• Straie (stretch marks) often appearing at a young age irrespective of weight fluctuation

Cardiac Concerns

The most serious and potentially life threatening problem associated with the Marfan syndrome involves the cardiovascular system.  At least 90% of Marfan cases have cardiac involvement in varying degrees.

The aorta, which is the main artery carrying blood away from the heart, is generally wider and more fragile in patients with the Marfan syndrome.  This widening is progressive and can cause leakage of the aortic valve or tears (dissection) in the aortic wall.  Surgical repair may be required in serious cases.

The two leaflets of the mitral valve may billow backwards when the heart contracts (mitral valve prolapse).  This may lead to leakage of the mitral valve or irregular heart rhythm.

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Diagnosis

Diagnosis at present relies on a clinical and co-ordinated evaluation by a cardiologist, ophthalmologist, orthopaedist, and geneticist who are all experienced with the Marfan syndrome.

Laboratory screening of the Marfan gene, using blood or skin samples, is currently available to identify the presence and familial location of faulty fibrillin protein responsible for Marfan.  Advances are currently being made in research to develop an accurate, quick and simple test.

The tests performed in an assessment of Marfan include:

• Physical examination
• Complete family history
• Echocardiogram (a sound wave picture of the heart)
• Eye examination using a slit lamp for the detection of dislocated lenses
• Skeletal examination including X-rays
• Laboratory screening for fibrillin

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Treatment

It is important that a person diagnosed with Marfan is well informed of their condition and receives customized medical management and treatment.  Understanding individual limitations will help the individual to accept relevant lifestyle changes to reduce stress on the body, particularly on the aorta.  Advice should be sought from the physician managing the individual’s condition appropriate to their own situation.  It is important to know and understand the risks associated with contact sports and specific physical activities.  A woman who has a dilated aorta requires specialised counseling about the higher risks involved when considering a pregnancy due to the associated strain on this major artery.

In general, treatment may include the following:

• Annual echocardiogram to monitor the size and function of the heart and aorta
• Surgical repair of valves and aorta, if necessary
• Initial eye examination to detect dislocated lenses with regular follow up by an ophthalmologist
• Careful monitoring of the skeletal system, especially during childhood and adolescence
• Beta-blocker medication may be prescribed to lower blood pressure and consequently reduce stress on the cardiovascular system
• Antibiotics may be prescribed prior to dental or genito-urinary procedures to reduce the risk of infection (endocarditis) in people who experience mitral valve prolapse
• Lifestyle adaptations such as avoidance of strenuous exercise and contact sports are often necessary to reduce the risk of physical injury

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What causes Marfan syndrome?

A defect in the protein called fibrillin was discovered in 1991 to be responsible for the Marfan syndrome.  This protein was traced to the suspected Marfan gene, confirming its location on the long arm of chromosome 15.  This error in the gene weakens and lessens the strength and elasticity of the connective tissue found throughout the body. 

Usually the gene is inherited from a parent who is affected by Marfan syndrome.  Marfan syndrome is an autosomal dominant disorder, meaning an affected person has a 50/50 chance of passing the Marfan gene on to their offspring.  Approximately one quarter of cases occur as a result of a spontaneous mutation (a change occurring in the gene) and thus is not inherited.

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