Marfan Syndrome

What is Marfan syndrome?

Marfan syndrome is a genetic disorder that affects the connective tissue, including the blood vessels of the heart and the heart valves.

Connective tissue gives strength and support to many parts of the body. Besides the blood vessels and heart valves, the tendons, ligaments and cartilage are all examples of connective tissue.

In Marfan syndrome, the connective tissue isn’t normal. As a result, certain body parts aren’t as strong as they should be. This can cause a range of symptoms from very mild to severe and life threatening.

Heart problems are usually the most serious problems in children with Marfan syndrome. The walls of their major arteries tend to be weak. Often, their aorta is affected. If it is, the aorta gets bigger. This weakens the inner wall of the aorta.

A weak inner aortic wall can result in an aneurysm (pronounced AN-yer-iz-em), an area where the wall bulges outward.

A weak inner aortic wall can also tear. Then blood can leak through the tears and separate the layers of the aorta. This problem is called aortic dissection.

  • Marfan syndrome is a genetic condition. Children who have Marfan are born with it.

    Children either inherit it from one of their parents or it is caused by a genetic change that happened in the child and wasn’t passed down from a parent. It’s important to identify which kind your child has, since this can make a difference in how your doctor treats the condition.

    If the condition was inherited, it may also affect one of the child’s parents or their brothers and sisters.

    Marfan syndrome affects about 1 in every 5,000 people.

Marfan Syndrome at Seattle Children’s


  • Our Heart Center is the top-ranked cardiology and cardiac surgery program in the Northwest and among the best in the nation, according to U.S. News & World Report. With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.

    Our heart team has treated many children with Marfan syndrome. We have extensive experience with the treatment these patients may require, including surgery in some cases. Our Cardiac Genetics Program combines the expertise of cardiology, medical genetics and genetic counseling. We also have a pediatric cardiac anesthesia team and a Cardiac Intensive Care Unit ready to care for children who undergo heart surgery.

    Seattle Children’s has been treating children since 1907. Our team members are trained in their fields and in meeting the unique needs of children. For example, the doctors who give your child anesthesia (sedation) are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

    The Adult Congenital Heart Disease Program shared by Seattle Children’s and the University of Washington can help with care throughout your child’s life.

  • When you come to Seattle Children’s, a team of people will take care of your child. Along with your child’s heart doctor (cardiologist), you are connected with newborn specialists (neonatologists), lung doctors (pulmonologists), nurses, child life specialists, social workers and others, if their expertise is needed.

    We’re committed to your child’s overall health and well-being. We’ll help your family through this experience and discuss treatments in ways you can understand and involve you in every decision.

    Read more about the supportive care we offer.

Symptoms of Marfan Syndrome

The symptoms of Marfan syndrome may vary greatly, even among children in the same family. Symptoms can range from mild to severe.

Some children have no symptoms early in life. But as they grow, they develop common Marfan symptoms and traits.

  • If you have a family history of Marfan syndrome, tell your doctors this when you are pregnant so they can check your newborn closely for signs of the condition.

    Newborns who have signs of Marfan may have more serious heart problems than children diagnosed at an older age.

    They may also have any of these problems:

    • Mitral valve prolapse (valves are “floppy” and don’t close right)
    • Blood that leaks backward through a heart valve (regurgitation)
    • Breathing problems
  • In children up to age 12, the most common symptoms are with the bones in their body (skeletal system). Your child may have these traits:

    • Tall and thin frame
    • Long, slender fingers, thumbs and toes
    • Breastbone that caves inward or pushes forward
    • Loose joints
    • Scoliosis
    • Flat feet
    • Vision problems
  • Many of the traits of Marfan syndrome may be quite mild early in life and become more noticeable as your child grows. So your child may not be diagnosed with Marfan syndrome until their teenage years.

    Along with the common traits listed above, your doctor will be looking for these signs and symptoms in your teen:

Diagnosing Marfan Syndrome

To diagnose this condition, your doctor will do a complete exam, checking your child for the physical traits of Marfan syndrome.

The doctor will ask about your child’s health history and your family’s health history.

Your child will need an echocardiogram test so the doctor can see how their heart works.

An eye doctor (ophthalmologist) will check your child for any vision problems.

Early diagnosis is important to your child’s future health. When Marfan is diagnosed early, your doctor can watch your child for problems that may require treatment. This may help prevent complications.

If one of your children has Marfan syndrome, your doctor may suggest doing genetic tests to see if one of their parents or a sister or brother has the condition.

Treating Marfan Syndrome

Not all children with Marfan syndrome need treatment. But all children with this condition need lifelong care to monitor their condition. Different symptoms may appear as your child gets older, so the doctor will want to watch for these.

Some children will need to take medicines that lower their heart rate or blood pressure or both. Children who have major problems with their aortaaortic valve or mitral valve may need surgery to repair or replace them.

To meet your child’s long-term healthcare needs, we have a special Adult Congenital Heart Disease Program to transition your child to adult care when they’re ready.

New treatments

Seattle Children’s is part of a national study to better understand treatment choices for the cardiac complications of Marfan syndrome. The study is comparing two drugs to determine which is more effective in reducing the tendency for the aorta to enlarge.

Contact Us 

Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.

Providers, see how to refer a patient.