Loeys-Dietz Syndrome

What is Loeys-Dietz syndrome?

Loeys-Dietz (LOW-eez DEETS) syndrome is a rare connective tissue disease. A gene change or mutation causes the disease. Loeys-Dietz syndrome can affect many organs such as the heart, blood vessels, bones, eyes and skin, causing life-threatening problems.

What does Loeys-Dietz syndrome mean?

This condition gets its name from two doctors: Dr. Bart Loeys and Dr. Hal Dietz. They first identified the distinct syndrome – and the gene mutations that cause it – in 2005. Before this discovery, healthcare providers attributed symptoms to Marfan syndrome. This connective tissue disease affects the body in similar ways.

What is a connective tissue disease?

Your connective tissues hold together structures in the body. They provide flexibility and strength to blood vessels, bones, ligaments, and muscles.

Connective tissue diseases affect collagen and elastin. These two proteins make up connective tissue. There are more than 200 connective tissue diseases. Each disease has distinct causes, symptoms and treatments. These diseases cause inflammation in the connective tissue. They damage the tissue and the structures they support.

How common is Loeys-Dietz syndrome?

Loeys-Dietz syndrome is a relatively new diagnosis. Medical experts don’t know how many people have this disease. It’s also unclear how many people have other types of connective tissue diseases.

What causes Loeys-Dietz syndrome?

Changes to certain genes cause Loeys-Dietz syndrome. An estimated 3 out of 4 people with Loeys-Dietz syndrome have no family history of the disease. For unknown reasons, a gene mutates or changes for the first time. This change is a de novo mutation.

Loeys-Dietz syndrome has an autosomal dominant pattern of inheritance, meaning one copy of the faulty gene is enough to cause the disorder. A parent with Loeys-Dietz syndrome has a 50% chance of passing the faulty gene that causes the disease to each of their children.

What are the types of Loeys-Dietz syndromes?

Different gene mutations cause five distinct types of Loeys-Dietz syndromes. All five types have similar symptoms. Providers identify the types by the underlying gene change. Types 1 and 2 are the most common.

Types of Loeys-Dietz syndromes (LDS) include:

• LDS-1: TGFβR1 (transforming growth factor beta-receptor 1).
• LDS-2: TGFβR2 (transforming growth factor beta-receptor 2).
• LDS-3: SMAD-3 (mothers against decapentaplegic homolog).
• LDS-4: TGFβ2 (transforming growth factor beta-2 ligand).
• LDS-5: TGFβ3 (transforming growth factor beta-3 ligand).

What are the symptoms of Loeys-Dietz syndrome?

The severity of symptoms for Loeys-Dietz syndrome varies from person to person, depending on the mutation. Symptoms may be present at birth or appear during childhood or adulthood. The disease can affect different parts of the body, causing a range of symptoms.

Cardiovascular symptoms of Loeys-Dietz syndrome:

Nearly everyone with Loeys-Dietz syndrome develops an enlarged aorta. The aorta is the largest artery in the circulatory system. It runs from the heart through the chest to the abdomen. Your aorta carries oxygenated blood to the body.

Enlargement stretches and weakens the aorta. This increases the risk of:

• Aortic aneurysm (bulge in the wall of the aorta).
• Aortic dissection (tear in the inner lining of the aorta).

Aneurysms and dissections can also develop in other arteries The artery wall may rupture or develop a hole. An aortic rupture is a life-threatening problem that requires emergency treatment. Symptoms include sudden, severe chest pain, shortness of breath and nausea and vomiting.

Loeys-Dietz syndrome also increases the risk of:

• Arterial tortuosity (arteries that twist or spiral).
• Pediatric and congenital heart defects.

Skeletal and musculoskeletal symptoms of Loeys-Dietz syndrome:

Loeys-Dietz syndrome can affect the musculoskeletal system. These effects may cause:

• Clubfoot (feet that turn inward) or flat feet (no arch).
• Craniosynostosis (early fusion of an infant’s skull bones).
• Degenerative disk disease (lack of cushion between spinal disks).
• Osteoarthritis (joint inflammation in the knees, wrists, hands or spine).
• Pectus excavatum (sunken chest) or pectus carinatum (protruding chest).
• Pediatric and adolescent scoliosis or adult scoliosis (spine curvature).

Other symptoms of Loeys-Dietz syndrome:

People with Loeys-Dietz syndrome are also more prone to:

• Allergies (including food allergies) and asthma.
• Easy bruising and scarring.
• Broad or split (bifid) uvula (the dangling tissue in the back of the throat).
• Cleft lip and palate.
• Digestive system problems like inflammatory bowel disease (IBD), abdominal pain and diarrhea.
• Osteoporosis and bone fractures.
• Overly flexible joints (hypermobility).
• Skin that’s translucent (see-through) and velvety soft.
• Widely spaced eyes (hypertelorism) and myopia (nearsightedness).

How is Loeys-Dietz syndrome diagnosed?

If you or your child shows signs of Loeys-Dietz syndrome, a geneticist (specialist in genetic conditions) may perform genetic testing. A blood test identifies gene mutations that cause the disease.

These tests can help diagnose cardiovascular conditions linked to Loeys-Dietz syndrome:

• Echocardiogram to check for aorta problems and heart defects.
• Computed tomography angiogram (CTA) or magnetic resonance angiogram (MRA) from head to pelvis to check for aneurysms and twisting arteries.

How is Loeys-Dietz syndrome treated?

Loeys-Dietz treatments are unique to each individual. Your care depends on the associated problems and symptoms. However, an aortic rupture is an emergency that requires immediate surgery.

Treatments for Loeys-Dietz syndrome include:

• Medications for blood pressure. These include angiotensin II receptor blockers (ARBs) and beta-blockers to lower the risk of aneurysms and dissections.
• Complex aorta surgery or Marfan syndrome heart surgery to prevent or treat aneurysms and dissections.
• Orthopedic surgeries and devices for clubfoot, scoliosis or other skeletal issues.
• Regular CTAs and MRAs to check for artery problems.
• X-rays to check for spine problems.

What are the complications of Loeys-Dietz syndrome?

People with Loeys-Dietz syndrome are at risk for:

• Collapsed lung (pneumothorax).
• Perforated bowel or bowel rupture (hole in the intestines).
• Retinal detachments.
• Ruptured spleen.

Can you prevent Loeys-Dietz syndrome?

If you have the gene change that causes Loeys-Dietz syndrome, you may want to meet with a genetic counselor. This specialist can discuss options that may lower the risk of passing the changed gene to your children.

Healthcare providers can use preimplantation genetic diagnosis (PGD) to select embryos that don’t have the faulty gene. Providers then use in vitro fertilization (IVF) to implant these healthy embryos into the uterus.

What is the outlook for people with Loeys-Dietz syndrome?

Loeys-Dietz syndrome is still a relatively new disease. Experts are still learning how it affects the quality of life and life expectancy. Increased disease awareness, earlier detection and treatments are helping people live long, full lives.

When should I call the doctor?

Call your healthcare provider if you experience:

• Signs of an aortic rupture, such as sudden chest pain or vomiting.
• Severe stomach upset or other gastrointestinal problems.
• Unexplained abdominal or back pain.

What should I ask my provider?

You may want to ask your healthcare provider:

• What type of Loeys-Dietz syndrome do I have?
• What is the best treatment for me?
• How can I lower my risk of cardiovascular problems and other problems?
• Should I get a genetic test?
• Should I look out for signs of complications?

What is the difference between Loeys-Dietz syndrome and Marfan syndrome?

These two connective tissue diseases affect the body in similar ways. The main difference is the underlying cause, which affects treatment. A gene change to the fibrillin-1 (FBN-1) protein causes Marfan syndrome. Several different gene mutations can cause Loeys-Dietz syndrome.

How does Loeys-Dietz syndrome affect pregnancy?

Pregnant women with Loeys-Dietz syndrome are at risk for uterine ruptures. The uterus may suddenly tear during pregnancy or labor and delivery. This rupture can be life-threatening to mother and child. It’s important to receive care from a perinatologist (maternal-fetal medicine doctor). This expert specializes in high-risk pregnancies. Your provider may recommend delivering early or via Cesarean section (C-section).

Can you exercise when you have Loeys-Dietz syndrome?

People with Loeys-Dietz syndrome should try to stay physically active. Exercise lowers the risk of obesity, which can strain the heart. It also promotes healthy blood pressure and heart rate.

Healthcare providers typically advise against high-contact sports like football, lacrosse and hockey. An impact during a game can cause a weakened aorta to tear or rupture. You should also avoid isometric exercises like sit-ups and pull-ups. These types of exercises can strain muscles. Activities like hiking, jogging, biking and swimming — at a level where you can safely carry on a conversation — are usually OK. Check with your healthcare provider first.