Marfan syndrome - Diagnosis 

A diagnosis of Marfan syndrome will be based on your medical and family history and a physical examination. There is no single test that can confirm a diagnosis of Marfan syndrome, but there are criteria that your GP will measure your symptoms against.

Medical history

Your GP will have a detailed look at your:

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

Physical examination

Your GP may also carry out a physical examination, including:

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

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

Sometimes, it may also be difficult to distinguish Marfan syndrome from other conditions that cause similar symptoms, such as Ehlers-Danlos syndrome or Beals syndrome (both conditions affect the body’s connective tissue).

Diagnosing children

Marfan syndrome can be particularly difficult to diagnose in children, and it is very rare for a young child to be definitively diagnosed with Marfan syndrome. This is because most symptoms of the syndrome will not usually appear until the child is a teenager or young adult.

A child with suspected Marfan syndrome will usually be carefully monitored, so that any developing symptoms can be detected and treated as soon as possible.

Ghent criteria

Your GP may examine your 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. Major criteria are features or symptoms that are common in people with Marfan syndrome and rare in people who do not have the condition. 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:

• If you have a family history of Marfan syndrome, you will need to have one major criterion and one minor criterion 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 minor criterion affecting 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 a curved spine (scoliosis)
• dural ectasia (enlargement of the lining that surrounds part of the spinal cord)

Minor criteria

Minor criteria can include:

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

Further testing

To help confirm your diagnosis, your GP may arrange for you to have further testing at a hospital or clinic. This will also help detect any potentially serious symptoms, such as an enlarged aorta. Some of the tests you may require may include:

• 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 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
• a 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

There is no single genetic test that can definitively diagnose Marfan syndrome. Although the gene (unit of genetic material) that causes Marfan syndrome has been identified, it can mutate in over 200 different ways. This means that devising a single test for Marfan syndrome is very difficult.

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

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, two possible tests may be used:

• chorionic villus sampling (CVS)
• amniocentesis

These tests are described briefly below.

Chorionic villus sampling (CVS)

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). The sample is then tested for genetic (inherited) conditions.

See the Health A-Z topic about Chorionic villus sampling for more information.

Amniocentesis

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

See the Health A-Z topic about Amniocentesis for more information.

Caution

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

The severity of Marfan syndrome in the parent is not 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.

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, and which could still cause Marfan syndrome.