Marfan syndrome

Marfan syndrome is a disorder of the body's connective tissues. These are a group of tissues that maintain the structure of the body and support internal organs and other tissues. Children usually inherit the disorder from one of their parents. There's no cure and treatment focuses on managing the symptoms.

Symptoms of Marfan syndrome

Some people are only mildly affected by Marfan syndrome, while others develop more serious symptoms.

Typical characteristics of Marfan syndrome include:

  • being tall 
  • abnormally long and slender limbs, fingers, and toes (arachnodactyly)
  • heart defects
  • lens dislocation – where the lens of the eye falls into an abnormal position

Causes of Marfan syndrome

Marfan syndrome is a hereditary gene defect. This means it can be passed to a child from a parent who's affected.

In around three-quarters of cases, Marfan syndrome is inherited from one parent. The syndrome is autosomal dominant. This means a child can inherit it even if only one parent has the syndrome.

The gene defect leads to abnormal production of a protein called fibrillin. This results in parts of the body being able to stretch abnormally when placed under any kind of stress.

The defective fibrillin gene also causes some bones to grow longer than they should. This means a person with Marfan syndrome may be tall because their arms and legs grow longer than normal.

In the remaining cases, neither parent has the syndrome. The fibrillin gene changes (mutates) for the first time in the parent's egg or sperm. The mutated gene can be passed on to the child, who will then go on to develop the syndrome.

Diagnosing Marfan syndrome

Diagnosing Marfan syndrome can be difficult as the symptoms can vary significantly from person to person.

As the symptoms of Marfan syndrome don't always develop during childhood, it may not be identified until the teenage years.

In most cases, a genetic test can be used to confirm a diagnosis of Marfan syndrome. 

In most cases, a diagnosis of Marfan syndrome is based on a thorough physical examination and a detailed assessment of a person's medical and family history.

Treating Marfan syndrome

There's no cure for Marfan syndrome. Treatment focuses on managing the symptoms and reducing the risk of complications.

One of the most serious problems caused by Marfan syndrome occurs if the heart and the aorta, the body's main artery, are significantly affected. This can lead to a lower life expectancy.

How common is Marfan syndrome?

Although Marfan syndrome is rare, affecting about one in 3,000 people, it's one of the most common connective tissue disorders. Men and women are affected equally.

The information on this page has been adapted from original content from the NHS website.

For further information, read terms and conditions.

This page was published July 2018

This page is due for review July 2019

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