Loeys-Dietz Syndrome

Loeys-Dietz syndrome is a rare, genetic condition that affects the formation of a child’s connective tissue. Connective tissue provides flexibility and strength to many structures in the body, including blood vessels, muscles, ligaments, and bones. When it does not form correctly, it can lead to problems with many areas in the body, including the cardiovascular system, musculoskeletal system, gastrointestinal system, and skin.

The most dangerous complication of Loeys-Dietz syndrome are aneurysms, caused by the stretching or dilation of arteries. Aneurysms can be life threatening.

Loeys-Dietz syndrome affects different people in different ways. Even among members of the same family, the signs and symptoms of Loeys-Dietz syndrome vary widely — both in their features and in their severity. Your child’s doctor can help you decide if your child should be evaluated for Loeys-Dietz syndrome.

Some of the signs and symptoms of Loeys-Dietz syndrome may include:

• Twisted or enlarged arteries
• Extreme looseness of joints or skin
• Skeletal problems, such as a sunken or protruding chest
• Skin that bruises easily
• Widely spaced eyes
• A split in the uvula (the tissue that hangs down in the back of the throat)

Loeys-Dietz syndrome is caused by a mutation (change) in one of the genes responsible for the formation of connective tissue in the body.

In about 25 percent of cases, a child with Loeys-Dietz syndrome has inherited a copy of the abnormal gene from a parent. In the other 75 percent, the change in the gene mutates spontaneously for no apparent reason.

Diagnosing Loeys-Dietz syndrome can be challenging because some children have very mild symptoms. Also, Loeys-Dietz syndrome is often confused with Marfan syndrome.

If your child’s doctor suspects Loeys-Dietz syndrome, they may order one or more of the following tests:

• Echocardiogram (cardiac ultrasound)
• Cardiac magnetic resonance imaging (MRI) or cardiac computed tomography (CT)
• Genetic testing to look for gene mutations

Treatment for Loeys-Dietz syndrome can vary, depending on your child’s specific symptoms, but may include medications or surgery.

Medications to treat Loeys-Dietz syndrome

The most serious complication of Loeys-Dietz syndrome is the rupture of an aneurysm. To manage aneurysms, your child’s doctor may recommend:

• Medications, such as beta blockers and Losartan, to help slow heart rate and lower blood pressure in the arteries to reduce the risk of rupture
• Close monitoring of your child's aorta and arteries for aneurysms
• Avoiding certain high-impact activities, such as competitive contact sports and weightlifting, because they can increase the chances of a rupture

Surgery to treat Loeys-Dietz syndrome

Many children with Loeys-Dietz syndrome require surgery to reduce the risk for rupturing or tearing of aneurysms, which can be life threatening. These aneurysms require careful monitoring and early surgical repair to prevent this severe complication.

Loeys-Dietz syndrome is a complex condition, and no single specialist is equipped to treat your child for all of their symptoms. At Boston Children’s, your child’s care team may include physicians from several disciplines, including cardiac surgery, cardiology, genetics, ophthalmology, orthopedics, plastic surgery, and general surgery. Each member of the team is experienced in treating children with Loeys-Dietz syndrome.

While there’s no cure for Loeys-Dietz syndrome, we have many ways of managing your child’s symptoms — so they can live a healthy, productive life.