Marfan syndrome is a genetic disorder that affects the body's connective tissue. Connective tissue holds the body's cells, organs, and other tissue together. Connective tissue is also important in growth and development.

Marfan syndrome is caused by an abnormal gene. The affected gene is FBN1. It helps make a protein in connective tissue called fibrillin-1. The abnormal gene happens as follows:

• In about 3 out of 4 cases, the gene is inherited from a parent who is affected. Each child of an affected parent has a 1 in 2 chance of having the disorder (autosomal dominant inheritance).
• In about 1 out of 4 cases, the abnormal gene is from  a new mutation. It is not inherited from a parent. Researchers believe this happens more often when the father is older than 45. The child also has a 1 in 2 chance of passing on the gene.

Marfan syndrome occurs about equally in boys and girls. It also occurs in all races and ethnic groups.

A child is more likely to have Marfan syndrome if he or she has a parent with the disorder.

A child with Marfan syndrome can have many different signs and symptoms. The syndrome can affect the heart and blood vessels, bones and joints, and eyes. Symptoms can occur a bit differently in each child. They can include:

• Abnormal facial appearance
• Eye problems such as nearsightedness
• Crowding of teeth
• Tall, thin body
• Abnormally shaped chest
• Long arms, legs, and fingers
• Laxity of joints
• Curved spine
• Flat feet
• Poor healing of wounds or scars on the skin 
• Dilation of the aortic root (the initial part of the aorta as it arises from the left ventricle)
• Mitral valve prolapse
• Pulmonary disease such as emphysema or spontaneous pneumothoraces

The symptoms of Marfan syndrome can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.

The healthcare provider will ask about your child’s symptoms and health history. They will give your child a physical exam. The health care provider will ask about any family history of Marfan syndrome. To be diagnosed with Marfan syndrome, your child must have some specific health problems affecting the heart, blood vessels, bones, and eyes.

Your child may also have tests, such as:

• Electrocardiography (ECG). A test that records the electrical activity of the heart. It shows abnormal rhythms (arrhythmias).
• Echocardiography. An exam of the heart that uses sound waves. It creates moving pictures of the heart.
• Dilated eye exam. A complete eye exam that includes the inside of the eye. 
• CT or MRI scans. Imaging tests that check for abnormal bones or joints.
• FBN1 gene testing. A blood test to check for the abnormal gene.

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

There is no cure for Marfan syndrome. Treatment is based on which organs are affected. Your child will be closely watched for problems by getting regular checkups, echocardiography, and complete eye exams.

Heart problems are treated by a pediatric cardiologist. This is a doctor with special training to treat heart problems in children. The treatment may include:

• Heart medicine. This includes beta-blockers. These medicines ease the work of the heart. As your child grows, they will probably need higher doses of the medicine.
• Surgery. This is to repair the aorta. It may be planned or it may be an emergency surgery. A child may also have surgery to repair heart valves. And some children may need a heart transplant.

Bone and joint problems are treated by a doctor with special training (orthopedist or orthopedic surgeon). Treatment may include braces, therapy, or surgery.

Eye problems are treated by an eye specialist (ophthalmologist). Treatment may include medicine or surgery.

Children with Marfan syndrome are at risk for serious complications, especially of the heart and blood vessels. They include:

• Mitral valve prolapse. An abnormal valve between the left atrium and ventricle of the heart. This allows blood to flow backward from the ventricle to the atrium.
• Fast, slow, or irregular heartbeat (arrhythmia or dysrhythmia)
• Aortic regurgitation. An abnormal valve between the aorta and left ventricle. This allows the blood to flow backward. The left ventricle has to work harder, and there is less blood flow to the rest of the body.
• Aortic dilation and dissection. An enlarged and weakened aorta. The aorta tears, and there is bleeding in the chest or belly (abdomen). Some dissections are medical emergencies.
• Heart failure. The heart is not able to pump as well as it should.
• Heart muscle disease (cardiomyopathy)

Children may also have complications affecting other body systems, such as:

• Collapsed lung
• Abnormally shaped spine (scoliosis)
• Inability to move joints (contractures)
• Increased eye pressure (glaucoma)
• Clouding of the lens (cataract)
• Detached retina, the layer of the back of the eye
• Skin changes

Most children with Marfan syndrome can expect to live long lives.

• Talk with your child's healthcare providers about physical activities that are safe for your child. 
• In general, children with Marfan syndrome should not take part in strenuous activities like weightlifting. They also should not take part in competitive sports that make the heart work harder.
• Children with some heart problems are more likely to get infections that affect the heart. These infections often start in the mouth. So good oral hygiene is important. Make sure your child takes good care of their teeth and gums every day. Your child should also have regular dental exams.
• A small number of children may need antibiotics before some dental and medical procedures. Talk with your child's healthcare providers about this.

Call your child's healthcare provider if you notice changes in your child. You will need to get medical help right away if your child has a worsening aortic dissection. Call 911 or your local emergency number if your child has:

• Severe chest pain, pain between the shoulder blades, or in the upper belly (abdomen)
• Signs or symptoms of shock, including:
  • Anxiety or nervousness
  • Blue color to lips and nails
  • Confusion
  • Dizziness
  • Pale, cool, or clammy skin
  • Shallow breathing
  • Loss of consciousness
  • Pain or trouble moving the arms or legs

• Marfan syndrome is a genetic disorder that affects the connective tissue.
• A child with Marfan syndrome may have problems with the bones and joints, heart and blood vessels, and eyes.
• A diagnosis of Marfan syndrome is based on signs, family history, and results of diagnostic tests.
• A child with Marfan syndrome is closely watched with physical exams and regular testing.
• Treatment is based on which organs and body systems are affected.
• A dissecting aorta can be a medical emergency.

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
• Ask if your child’s condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if your child does not take the medicine or have the test or procedure.
• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.