Marfan Syndrome

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is Marfan syndrome?

As a genetic connective tissue disorder, Marfan syndrome causes errors in the body’s production of a protein called fibrillin. Fibrillin supports the formation of connective tissue within structures like blood vessels, nerves, and cartilage pads (menisci). Without adequate amounts of fibrillin, those structures become weak, which can lead to serious complications. In the case of the aorta, for example, a weakened area in the lining of the artery wall can balloon out as an aneurysm. Since virtually all of the body’s structural components require fibrillin, Marfan syndrome can impact many vital functions, including breathing, circulation, vision, and nerve conduction.

Marfan syndrome affects about 1 in 5,000 people of all ages and races in the United States, independent of gender. Most people with Marfan inherit the condition from one or both parents through a genetic abnormality, though roughly 1 in 4 people with Marfan will be the first in their family to develop the disorder. Although the syndrome always affects the body’s connective tissue, Marfan syndrome symptoms vary from person to person, even among people in the same family.

Doctors cannot cure Marfan syndrome, but they can help patients manage it with early diagnosis, medical monitoring, and intervention. Today, Marfan syndrome life expectancy can be the same as it is for people without the condition.

What are the symptoms of Marfan syndrome?

Because Marfan syndrome can affect nearly every body system, the symptoms of the condition can vary from person to person. People with the condition generally exhibit certain traits, or Marfan syndrome signs including:

  • Tall and thin build with unusually long arms, legs, fingers and toes
  • Unusually flexible joints
  • Scoliosis (curvature of the spine)
  • Sunken or protruding chest (pectus deformity)
  • Crowded teeth
  • Flat feet
  • Eye and vision problems including nearsightedness, dislocated lenses, and increased risk of cataract, glaucoma, and retinal detachment
  • Heart-related symptoms, such as palpitations or heart murmur

Not everyone with Marfan syndrome will exhibit every trait. Some people may have many traits, while other people have few.

What causes Marfan syndrome?

What causes Marfan syndrome? Marfan syndrome results from abnormalities in the gene responsible for fibrillin production, FBN1. Different mutations in the FBN1 gene can reduce the amount of fibrillin and cause connective tissue problems. Parents pass these gene mutations to their children. A child can develop Marfan syndrome if only one parent has the condition. Marfan syndrome genetics predict that a parent with Marfan syndrome has a 50% chance of passing the condition to each child.

Marfan syndrome diagnosis

A doctor diagnoses Marfan syndrome based on:

  • Family history of Marfan diagnosis
  • Eye lens dislocation, a specific defect called ectopia lentis
  • Size of the aorta—whether it is larger in diameter, or dilated compared to a normal individual of the same age and gender
  • Physical characteristics
  • Skin biopsy to determine the presence of fibrillin
  • Genetic testing identifying FBN1 mutations, or mutations in the TGFBR1 or TGFBR2 genes, which are also linked to Marfan symptoms

Because many different mutations in the FBN1 or TGFBR genes can cause Marfan syndrome and related conditions, there is no single ‘Marfan syndrome test.’ Rather, doctors order a combination of genetic tests to study the patient’s genes in more detail. Marfan syndrome genetic testing may be in order if a patient has some, but not all signs and symptoms of Marfan syndrome. This is because some signs, such as an enlarged aorta, may not be clear until later in life. Also, there are other genetic connective tissue disorders that resemble Marfan syndrome.

What are the risk factors for Marfan syndrome?

The main risk factor for Marfan syndrome is having a family history of the condition. However, a child of a parent who has Marfan syndrome has a 50% chance of having Marfan syndrome. If you have a family history of Marfan syndrome, you should have a comprehensive physical exam, cardiovascular evaluation, and possibly genetic testing. You should also be evaluated if you have a family history of an early cardiovascular-related death.

If you are diagnosed with Marfan syndrome, your children, parents and siblings should be checked by a cardiologist, a medical geneticist, and possibly other specialists for Marfan syndrome genetic defects and medical signs and symptoms, such as an enlarged aorta or spine problems.

How is Marfan syndrome treated?

Because there is no cure for the condition, Marfan syndrome treatment aims to prevent complications based on your specific signs, symptoms, and affected body systems. Treatment for Marfan syndrome may include:

  • Assistive devices like a brace to support the spine if you develop scoliosis
  • Medicines to slow your heartbeat and reduce your blood pressure, which reduces the risk of aortic dissection and aneurysm
  • Medicines and therapies to relieve pain
  • Medicines to treat complications like glaucoma
  • Surgery to treat serious heart-related conditions, bone and joint abnormalities, or other complications

What are the potential complications of Marfan syndrome?

The most serious potential complications of Marfan syndrome involve the heart. Aortic aneurysm, a potentially life-threatening bulge in the wall of this major artery, is the most common major complication in people with Marfan syndrome. Other common complications of Marfan syndrome include:

  • Dural ectasia, a condition in which the sac inside the spinal canal that contains the spinal fluid balloons outward and leads to erosion of the vertebrae or the nerve roots
  • Eye problems, including early glaucoma and dislocated lens (ectopia lentis)
  • Excessive pressure on the heart and lungs from a sunken chest
  • Mitral valve prolapse
  • Pneumothorax (collapsed lung)
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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Jan 24
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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  2. Marfan Syndrome. National Institute of Arthritis and Musculoskeletal and Skin Diseases.
  3. Marfan Syndrome. MedlinePlus, U.S. National Library of Medicine.
  4. Getting Diagnosed. The Marfan Foundation.
  5. Ectopia Lentis Syndrome. The Marfan Foundation.
  6. Marfan Syndrome. Genetics Home Reference.
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