Marfan syndrome: what it is, symptoms, diagnosis and treatment

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, according to the NHS. Children usually inherit the disorder from one of their parents. Some people are only mildly affected, while others develop more serious symptoms.

The NHS says that although Marfan syndrome is rare, affecting about 1 in 5,000 people in the UK, it is one of the most common connective tissue disorders.

The NHS says Marfan syndrome can affect many parts of the body, including the skeleton, eyes, and heart and blood vessels, and that the severity of symptoms varies between individuals. Symptoms tend to get more severe as a person gets older.

If your child is particularly slim or tall for their age, the NHS says it does not necessarily mean they have Marfan syndrome; it is rare, and a child will usually have a number of other symptoms if they have it.

The NHS says Marfan syndrome can affect the cardiovascular system, and it is particularly serious if the aorta and heart valves are affected. In some people the walls of the aorta, the main artery in the body, are weak. This can cause the aorta to enlarge and balloon, and in severe cases the aorta can split (rupture), causing internal bleeding that can lead to death.

In some people the mitral or tricuspid valves do not close properly and blood leaks back through the valve, and the aortic valve may also leak, causing the main pumping chamber to gradually become enlarged. The NHS says Marfan syndrome can cause serious heart problems, which can be fatal, which is why the heart is treated as a priority.

The NHS says Marfan syndrome is hereditary and autosomal dominant, which means a child can inherit it even if only one parent has the syndrome, giving a 1 in 2 chance. In around 3 in 4 cases it is inherited from one parent. In the remaining 1 in 4 cases neither parent has the syndrome, and the fibrillin gene changes for the first time in the parent's egg or sperm.

The gene defect leads to reduced production of a protein called fibrillin, resulting in parts of the body being able to stretch abnormally under stress. The defective gene also causes some bones to grow longer than they should, which is why people may be tall with long arms and legs.

The NHS says Marfan syndrome can be difficult to diagnose because signs and symptoms vary from person to person. In most cases a diagnosis is based on a thorough physical examination and a detailed assessment of medical and family history. A GP or geneticist may compare symptoms against the Ghent criteria, a checklist with major and minor features, where a certain number of features plus either a relative with Marfan syndrome or an abnormal genetic test is needed.

Further tests may include an eye examination by an ophthalmologist to check for lens dislocation, an echocardiogram to check the heart and aorta, and an MRI scan to examine the aorta and detect dural ectasia. The NHS says a genetic test can detect an error that causes the syndrome in 99 in 100 of those affected, though in most cases the diagnosis is made from physical features and symptoms.

In children, the NHS says it can be particularly difficult to diagnose, and it is rare for it to be diagnosed in a young child, because most of the signs do not appear until later childhood and the teenage years. If suspected, a child will be carefully monitored.

The NHS says there is currently no cure. Treatment focuses on managing symptoms and reducing the risk of complications, and involves a team that may include a geneticist, genetic counsellor, cardiologist, ophthalmologist, orthopaedic surgeon and paediatrician, with a doctor assigned to coordinate care.

For the heart, the NHS says regular check-ups with a cardiologist, including regular echocardiograms to monitor the aorta, are needed. Beta blockers are often prescribed to slow the heart rate and decrease the strength of the heartbeat, which helps slow down enlargement of the aorta, and an angiotensin receptor blocker such as losartan or irbesartan may be used if beta blockers cannot be taken. The most common heart surgery is an operation to replace a section of an enlarged aorta, which must be carried out before the aorta becomes too big.

For the eyes, annual check-ups may be needed, with surgery for cataracts, treatment for glaucoma with eye drops, laser or surgery, and glasses or contact lenses for short-sightedness. For the skeleton, treatment includes pain relief and moderate exercise for joints, monitoring or a back brace for mild scoliosis, and surgery if the spine curves by 40 degrees or more.

The NHS says it is not usually necessary to make significant lifestyle changes, but that keeping fit through regular moderate exercise and eating a balanced diet will help improve overall health. A young person's career choice may be restricted.

You may be advised to avoid some sports. The NHS lists contact sports such as rugby, long-distance running, heavy weightlifting, gymnastics, climbing and scuba diving as activities that place a strain on the heart, raise blood pressure and heart rate and may increase the risk of an aortic tear, and also strain weak joints. Your cardiologist will advise which activities are suitable.

The NHS says emergency surgery will be needed if the aorta ruptures or tears. The NHS Marfan pages do not list warning symptoms, so as standard emergency advice, sudden severe pain in the chest, back or abdomen, or collapse, in someone with Marfan syndrome should be treated as an emergency: call 999.

If your GP thinks you may have Marfan syndrome, the NHS says you will be referred to a specialist for testing. Tell your clinical team promptly about new vision changes, as the NHS says eye problems can be potentially serious and may lead to permanent loss of vision.

On the NHS, a GP refers you to a specialist, and care is coordinated by a multidisciplinary team. The NHS says your clinical team passes information about people with Marfan syndrome on to the National Congenital Anomaly and Rare Disease Registration Service (NCARDRS) to help researchers, and you can opt out at any time. Prenatal testing (chorionic villus sampling or amniocentesis) and preimplantation genetic diagnosis are options for people who carry a known gene change and are planning a family.

Private genetic testing and cardiology review exist alongside, but because Marfan syndrome needs coordinated lifelong monitoring across the heart, eyes and skeleton, make sure any private findings are shared with your NHS team.