Marfan Syndrome

Systemic Conditions Affecting the Feet· Also known as: Marfan's syndrome, Marfan'sUpdated Nov 2026

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, November 2026

At a Glance

Marfan syndrome is an inherited condition of the connective tissue, the material that supports your bones, muscles and organs. About 1 in 5,000 people have it. It mainly affects the aorta (the body's main artery), the bones and joints, and the eyes. Many people are tall with long limbs and loose joints, and flat feet are common. How mild or severe it is varies a lot from person to person. Looking after the aorta is the most important part of long-term care.

What is it?

Marfan syndrome is an inherited condition of the connective tissue. This is the tissue that holds your body together and supports your bones, muscles and organs. You are born with it. It is usually caused by a change in a gene called FBN1, which makes a protein called fibrillin-1. This protein forms stretchy fibres in connective tissue.

The condition mainly affects the heart and blood vessels, the bones and joints, and the eyes. It can also involve the lungs, skin and nervous system. Some people have only mild signs in one or a few parts of the body. Others have severe disease in many organs that gets worse quickly, and this form can start in newborns.

Who does it affect?

About 1 in 5,000 people have Marfan syndrome, which is roughly 1.6 million people worldwide. It affects men and women alike, and people of all ethnic backgrounds.

Because it is inherited, it can run in families. But it can also appear in a family for the first time. More on that is in the causes section below.

Signs and symptoms

The main signs involve the heart and blood vessels, the bones and joints, and the eyes. Not everyone has all of them. Bone and joint signs are often the first clue. They can include:

being taller than expected, with long arms, legs, fingers and toes
an arm span that is greater than your height
loose joints
a curved spine (scoliosis)
a chest wall that sinks in or sticks out
a long, narrow face and crowded teeth
stretch marks, hernias, a heart murmur and breathlessness

In the foot, people usually have flat feet (pes planus).

The aorta is the large artery that carries blood from your heart. In Marfan syndrome its wall can be weaker, and the part nearest the heart (the aortic root) can widen. This can make the aortic valve leak or lead to a tear in the aorta wall, called an aortic dissection. It is the main cause of serious illness and death in Marfan syndrome. Rarely, sudden cardiac death is the first sign that something is wrong.

A few signs can mean something more serious is going on:

Chest pain, back pain or fainting can be signs of aortic dissection, a life-threatening emergency. Chest pain is the most common symptom, and it can be sudden and crushing.
Back pain that doesn't go away, or headaches that are worse when upright, can come from dural ectasia. This is a widening of the sac around the spinal cord, and it is found in more than 80 per cent of people who already have a diagnosis.
Changes in vision can come from eye problems such as glaucoma or retinal detachment. Most eye problems appear before age 30.
Pregnancy raises the risk of aortic dissection, and the risk stays higher for up to 12 weeks after delivery. The risk also rises as the aorta gets larger. When the aortic root is wider than 4.5 cm, pregnancy is generally advised against.

What causes it?

Marfan syndrome is caused by a harmful change in the FBN1 gene. This means there is less fibrillin-1, or it doesn't work properly. The elastic fibres in connective tissue then become fragile. Parts of the body can stretch more than they should under stress, and some bones grow longer than usual.

The condition is passed on in an autosomal dominant pattern. This means a child of a parent with Marfan syndrome has a 1 in 2 (50 per cent) chance of inheriting it. About 25 per cent of cases are new: the gene change happens for the first time in the affected person, so there is no family history.

A family history of Marfan syndrome, or of an aortic aneurysm (a bulge in the aorta) or dissection, is useful information for your health professionals to have.

How is it diagnosed?

Diagnosis uses a set of criteria called the revised Ghent criteria. They bring together a genetic test result, a body score based on the signs above, displacement of the lens of the eye (ectopia lentis), and family history.

Several other conditions overlap with Marfan syndrome, so sorting them out matters. These include Loeys-Dietz syndrome, Shprintzen-Goldberg syndrome, the MASS phenotype, and familial thoracic aortic aneurysm and dissection that doesn't come with other signs. Ehlers-Danlos syndrome is another inherited connective tissue condition. Broken bones are less common in Marfan syndrome (about 17 per cent of people) than in Ehlers-Danlos syndrome (44 per cent) or Loeys-Dietz syndrome (69 per cent).

Treatment

Care is usually shared between several practitioners, including a cardiologist (a heart specialist) and an eye specialist. The main aims are to protect the aorta and to avoid unnecessary strain on the joints.

Looking after it at home

Advice about activity is the same across the sources, and it is about balance. Contact sports, competitive sports, high-intensity exercise and isometric exercise (static, straining effort, such as heavy lifting) are generally advised against. They put extra stress on the aorta, can cause chest or eye injury, and can damage loose joints. Substances that stimulate the heart and circulation or narrow blood vessels are also generally avoided.

Gentle to moderate activity such as swimming, walking and cycling is generally encouraged. Regular moderate exercise and a balanced diet support your general health. Your cardiologist can advise which sports and activities suit you. How much these limits lower the risk of dissection isn't clear yet.

Loose joints can be injured more easily, so activity advice may need to be tailored to the person, especially for children and young people. Taking care during activity helps avoid unnecessary strain on joints. Between ages 12 and 16, school sport and activities outside school become more competitive, so some may need to be adapted or swapped for others.

Treatment from your podiatrist

Flat feet are the usual foot sign. Your podiatrist can look at how your feet and joints are coping as part of your wider care. It isn't yet clear how well shoe inserts (orthoses), insoles or footwear help flat feet or foot pain in Marfan syndrome.

Medicines

Medicines called angiotensin receptor blockers (ARBs) can slow the growth of the aorta. Their effect on aortic growth is particularly large in people who have a confirmed FBN1 gene change. Your doctor or cardiologist decides whether a medicine suits you.

Surgery

Treatment for aortic dissection is immediate surgical repair. The risk of dissection or rupture rises with the size of the aorta and with pregnancy, and a cardiologist manages this. How well other operations on the aorta, spine or feet work in Marfan syndrome isn't clear yet.

Recovery

Marfan syndrome is lifelong, so the focus is on long-term care rather than recovery. Outlook varies widely. Some people have mild signs, and others have severe disease.

The aorta has the biggest effect on outlook. A widened aortic root and dissection are the main reasons life expectancy can be shortened. Dissection of an aortic aneurysm is the greatest threat to life. The most severe form starts in newborns and generally has a poor outlook.

Preventing it

Marfan syndrome is inherited, so it can't be prevented. What can be reduced is the strain on the aorta and joints. That means keeping up regular moderate activity and a balanced diet, steering clear of the high-risk activities described above, and taking care to protect your joints during activity.

Frequently asked questions

Can I pass Marfan syndrome on to my children?

Yes. Because it is autosomal dominant, a child of a parent with Marfan syndrome has a 1 in 2 (50 per cent) chance of inheriting the gene change. Severity can differ between family members, even with the same gene change.

Can Marfan syndrome appear if no one in my family has it?

Yes. About 25 per cent of cases are new. The gene change happens for the first time in the person affected, so there is no affected parent and no family history.

Does everyone with Marfan syndrome look the same?

No. Many people are tall with long limbs, fingers and toes, but not everyone has the full set of features. Some people have mild signs in just one or two body systems, while others are affected much more widely.