Marfan syndrome - Diagnosis 

Diagnosing Marfan syndrome 

Marfan syndrome can be difficult to diagnose because the signs and symptoms can vary from person to person.

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

There are a number of criteria that your GP or geneticist (gene specialist) will measure your symptoms against (see below).

Physical examination

Your GP will carry out a physical examination that will include:

  • listening to your heart
  • checking your skin for stretch marks
  • looking for any physical features of the syndrome, such as long, thin arms

As well as the varied symptoms of Marfan syndrome, it can also sometimes be difficult to distinguish the syndrome from other conditions that affect the body's connective tissue, such as Ehlers-Danlos syndrome or Beals syndrome.

Medical history

As well as carrying out a physical examination, your GP will have a detailed look at your:

  • medical history – to find out whether you have had any symptoms or illnesses in the past that may be a sign of Marfan syndrome
  • family history – having a close family member with Marfan syndrome can increase your chances of also having the syndrome 


Marfan syndrome can be particularly difficult to diagnose in children, and it is very rare for the condition to be confirmed in a young child. This is because most of the syndrome's signs and symptoms do not usually appear until the teenage years.

If Marfan syndrome is suspected, the child will be carefully monitored so that any developing symptoms can be detected and treated as soon as possible.

Ghent criteria

Your GP may compare your signs and symptoms against the Ghent criteria. This is a diagnostic tool that helps GPs and other healthcare professionals tell the difference between Marfan syndrome and other, similar conditions.

The Ghent criteria consist of major and minor criteria. The major criteria are features or symptoms that are common in people with Marfan syndrome and rare in people who do not have the syndrome.

Minor criteria are features or symptoms that are present in people with Marfan syndrome, but are also present in people who do not have it.

To be diagnosed with Marfan syndrome using the Ghent criteria, you must have a number of different criteria as described below.

  • If you have a family history of Marfan syndrome, you will need to have one of the major criteria and one of the minor criteria that affect different systems in your body, such as your skeleton and your blood vessels.
  • If you do not have a family history of Marfan syndrome, you will need to have two major criteria and one of the minor criteria that affect different systems in your body.

Some of the different criteria that your GP may use are outlined below.

Major criteria

Major criteria can include:

  • an enlarged aorta (main artery)
  • a tear in the aorta
  • dislocation of the lens of the eye
  • a family history of the syndrome
  • at least four skeletal problems, such as flat feet or scoliosis (a curved spine)
  • dural ectasia (enlargement of the lining that surrounds part of the spinal cord)

Minor criteria

Minor criteria can include:

  • myopia (short-sightedness)
  • unexplained stretch marks
  • loose joints
  • a long, thin face
  • a high, arched palate (roof of the mouth)

Further testing

Your GP may arrange for you to have some additional tests at a hospital or clinic. This will help detect any potentially serious symptoms, such as an enlarged aorta. Some of the tests that you may have are detailed below:

  • an eye examination – which will be performed by an ophthalmologist (a doctor who specialises in eye conditions) to check for dislocation of the lens
  • an echocardiogram – which uses sound waves to produce an image of your heart and can also check for any problems with your aorta
  • a chest X-ray – an imaging technique that uses high-energy radiation to highlight abnormalities in bones and certain body tissue, such as the heart and lungs
  • magnetic resonance imaging (MRI) scan – which uses a strong magnetic field and radio waves to produce a detailed image of the inside of your body, and can be used to examine your aorta and other blood vessels and to detect dural ectasia

Genetic testing

Although the gene that causes Marfan syndrome has been identified, it can mutate (change) in over 1,000 different ways. Genes are single units of genetic material.

A genetic test can be used to examine the gene that is responsible for Marfan syndrome, and it can detect an error which causes the condition in 97% of patients. However, the test takes three months to complete and is very expensive.

As testing for the different gene mutations that can occur in Marfan syndrome is a costly and time-consuming process, in most cases a diagnosis will be made from the physical features and symptoms of the syndrome.

Read more about genetic testing.

Prenatal testing

If you have Marfan syndrome and you are going to become a parent, you may want to have your unborn baby tested to find out whether they also have the condition. To do this, there are two possible tests that can be used:

  • chorionic villus sampling (CVS)
  • amniocentesis

These tests are described below.

Chorionic villus sampling

Prenatal testing for conditions such as Marfan syndrome can be carried out approximately 10-12 weeks into the pregnancy using chorionic villus sampling (CVS).

CVS involves taking a small sample of cells from the placenta (the organ that links the mother’s blood supply with her unborn baby’s) through the entrance of the womb. The sample can then be tested for genetic conditions.

Read more about chorionic villus sampling.


Marfan syndrome can also be tested for using amniocentesis. This test is carried out about 16-18 weeks into the pregnancy. It involves taking a small sample of amniotic fluid for examination. Amniotic fluid surrounds the unborn baby in the womb.

Read more about amniocentesis.


It is important to remember that although prenatal tests may show whether your child has the defective gene, they will not give you any indication as to how serious their Marfan syndrome will be.

The severity of Marfan syndrome in the parent is an indication of how severe the syndrome will be in the child. Your child may only experience very mild symptoms, despite having the genetic mutation. This is because the expression of the gene can vary, even within the same family. 

In some cases, the results of CVS or amniocentesis could be negative, suggesting that your child does not have the defective gene. However, your child may have a different genetic mutation that was not tested for, which could still cause Marfan syndrome.

Page last reviewed: 09/05/2012

Next review due: 09/05/2014


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