Marfan syndrome

Marfan syndrome is a disorder of the body's connective tissues – a group of tissues that maintain the structure of the body and support internal organs and other tissues.

Children usually inherit it from one of their parents.

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

Read more about the symptoms of Marfan syndrome.

What causes Marfan syndrome?

Marfan syndrome is hereditary, which means it's passed to a child from their affected parent.

In around three-quarters of cases, Marfan syndrome is inherited from one parent. In the remaining quarter of cases, neither parent has the syndrome.

There's a one in two chance that the child of a person with Marfan syndrome will have the syndrome.

The gene defect leads to abnormal production of a certain protein called fibrillin, resulting 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 that someone with Marfan syndrome may be tall because their arms and legs grow longer than normal.

Read more about the causes of Marfan syndrome.

Diagnosing Marfan syndrome

Diagnosing Marfan syndrome can be difficult because 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.

A genetic test can be used to definitively confirm Marfan syndrome by closely studying the affected gene. However, it's a time consuming and expensive process as the gene can mutate in more than 1,000 different ways.

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.

Read more about how Marfan syndrome is diagnosed.

Treating Marfan syndrome

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

As Marfan syndrome affects several different parts of the body, treatment involves a number of healthcare professionals working together as a team. You'll be closely monitored and any complications will be treated if they occur.

The life expectancy of someone with Marfan syndrome may be reduced if the heart and aorta (the body's main artery) are significantly affected.

Read more about the possible treatments for Marfan syndrome.