Klippel-Trenaunay Syndrome

Klippel-Trenaunay syndrome (KTS) is a rare congenital condition. It causes a port-wine stain birthmark and problems with veins, bones or soft tissues.


What is Klippel-Trenaunay Syndrome?

Klippel-Trenaunay syndrome (KTS) is a rare congenital disorder. Congenital means it’s present at birth.

KTS causes a red “port-wine stain” birthmark. It also changes the way your soft tissues, bones and blood vessels develop. Many people with KTS also have abnormalities in their lymphatic system, which helps maintain fluid balance in the body.

Klippel-Trenaunay syndrome doesn’t have a cure, but treatment can help manage symptoms. Healthcare providers often identify and diagnose KTS shortly after a baby is born. Early diagnosis and treatment can reduce the risk of health complications related to KTS.

Where does Klippel-Trenaunay syndrome get its name?

KTS gets its name from the two French doctors who discovered it, Maurice Klippel and Paul Trenaunay. They identified the syndrome in 1900.

Is KTS related to Parkes Weber syndrome?

KTS and Parkes Weber syndrome are different but related conditions. In the early 1900s, a dermatologist named Frederick Parkes Weber noticed that some people had an overly large limb with a distinctive birthmark.

At the time, researchers thought it was the same as KTS. They used to call KTS “Klippel-Weber-Trenaunay syndrome” after all three researchers.

Now we know that Parkes Weber syndrome is a different condition caused by a different gene change (mutation). It doesn’t cause lymphatic changes of KTS.


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What is CLVM?

Some providers use the abbreviation CLVM to refer to Klippel-Trenaunay syndrome. CLVM refers to the changes in your:

  • Capillaries (C), the small blood vessels connecting your veins and arteries.
  • Lymphatic system (L), the part of your immune system that transports a body fluid called lymph.
  • Veins (V), the blood vessels that carry blood to your heart.

The M is for malformation, meaning a part of your body that hasn’t developed typically.

How rare is Klippel-Trenaunay Syndrome?

Experts estimate that KTS affects around 1 in 100,000 people around the world. It’s equally common in people assigned male at birth and people assigned female at birth.


Symptoms and Causes

What causes Klippel-Trenaunay syndrome?

KTS often occurs because of a change (mutation) in the PIK3CA gene. The gene change occurs sporadically (for no known reason). You don’t receive the gene from your parents.

Some people have KTS without having the PIK3CA mutation. Because of this, researchers think other gene mutations could also cause KTS.

What are the symptoms of Klippel-Trenaunay syndrome?

Klippel-Trenaunay syndrome causes four main signs and symptoms:

  • Capillary malformation (CM): KTS causes a port-wine stain birthmark, caused when capillaries swell directly beneath your skin. These birthmarks may be light pink to deep wine-red. They may lighten or darken as you age. Sometimes, small blisters form over the birthmark. As you get older, these blisters may burst or bleed. The port-wine stain is usually the first sign of KTS.
  • Vein malformation (VM): Venous malformations are seen in almost all people with KTS. Malformations may occur in superficial veins, leading to varicose veins on your calves and thighs. Varicose veins are twisted and swollen veins that may itch or hurt. Malformations may also occur in deeper veins, which may increase your risk of deep vein thrombosis (DVT). Blood flow problems can cause swelling and pain in your lower limbs. Venous malformations in the gastrointestinal (GI) tract can cause recurrent GI bleeding.
  • Soft tissue and bone overgrowth: Your limbs may grow longer or bigger than typical proportions, starting in infancy. Overgrowth often affects only one limb, usually your leg, leading to limb-length discrepancy (one leg might grow longer than the other). This difference can cause pain or a heavy feeling and can decrease your range of motion.
  • Lymphatic malformation (LM): Some — not all — people with KTS also have extra or unusual lymph vessels. Lymph vessels carry clear fluid called lymph throughout your body. Lymph contains infection-fighting cells and intestinal fluid. In KTS, the extra lymph vessels often don’t work as they should. They may leak lymph fluid or cause foot swelling. You may have problems with the lymph vessels in your pelvis, bladder or lower intestines.

KTS may cause complications such as:

Rarely, people with KTS also have congenital hand differences or toe differences, such as:

  • Extra fingers or toes (polydactyly).
  • Fused (joined) fingers or toes (syndactyly).


Diagnosis and Tests

How is Klippel-Trenaunay syndrome diagnosed?

Healthcare providers initially diagnose KTS based on the physical signs. Because many KTS symptoms are present at birth, you or your baby may receive a diagnosis of KTS before leaving the hospital.

Tests for Klippel-Trenaunay syndrome may include:

  • CT scans or MRIs to look at soft tissues and bones.
  • Magnetic resonance (MR) angiography, a specialized MRI to look at blood vessels and veins.
  • Color Doppler ultrasound to look at how blood flows through veins and arteries.

Management and Treatment

How is Klippel-Trenaunay syndrome treated?

Klippel-Trenaunay syndrome treatment varies based on symptoms. Treatment may include:

  • Blood-thinning medicines: Anticoagulants such as heparin reduce the risk of blood clots in the legs and pulmonary embolism.
  • Compression stockings: These special socks help blood return to the heart. They can decrease leg swelling and pain and reduce clot risks.
  • Endovenous thermal ablation: This treatment uses focused beams of energy inside blood vessels to close off problem veins. The veins stay in place so that you can heal faster, with less pain.
  • Laser therapy: Focused, strong beams of energy can destroy or remove unwanted tissue. You may have laser therapy to lighten the appearance of port-wine stain birthmarks.
  • Sclerotherapy: Your provider injects a special solution into specific veins or lymphatic vessels to close them off. Sclerotherapy is often effective for varicose veins.
  • Shoe lifts: You may wear a lift in one shoe to correct uneven leg lengths. Lifts can help prevent irregular spine curving (scoliosis).
  • Surgery: You may have surgery to correct vein problems or uneven leg length. Or your provider may remove some extra fat or tissue to reduce the size of overgrown limbs. Rarely, healthcare providers may amputate an irregularly large toe so you can wear shoes and walk more easily.


How can I prevent Klippel-Trenaunay syndrome?

Because KTS happens unpredictably, there’s no way to prevent it. Treatment can help people with KTS live a higher quality of life.

Outlook / Prognosis

Is there a cure for Klippel-Trenaunay syndrome?

No. There’s no cure for Klippel-Trenaunay syndrome, but treatment can help you manage symptoms.

The outlook for KTS can vary. People with the condition usually live a typical lifespan, but treatment is crucial. KTS can cause life-threatening complications, such as internal bleeding. Ongoing treatment with your healthcare provider can lower your risk of these complications.

Living With

What else should I ask my doctor?

If you or your child has KTS, you may also want to ask your healthcare provider:

  • What tests do I or my child need?
  • When will I get the results of the tests?
  • What are the treatment options?
  • Where can I learn more about Klippel-Trenaunay syndrome?

Additional Common Questions

Is Klippel-Trenaunay syndrome life-threatening?

KTS itself doesn’t affect life expectancy. But some KTS complications, such as internal bleeding or pulmonary embolism, can be life-threatening. Getting ongoing treatment for these risks can reduce the danger of these complications.

Is Klippel-Trenaunay syndrome a disability?

It can be. If KTS complications, such as deep vein thrombosis or pulmonary embolism, prevent you from working, you may qualify for disability benefits. For other issues, such as trouble walking due to limb growth, you may be eligible for accommodations such as a disability parking tag to make your life a little easier.

A note from Cleveland Clinic

Klippel-Trenaunay syndrome is a rare congenital disorder. Babies born with KTS typically have a port-wine stain birthmark, bone or soft tissue overgrowth and vein malformations. Healthcare providers often identify KTS early and may diagnose it before a newborn leaves the hospital. With treatment, most people with KTS can live a typical life.

Medically Reviewed

Last reviewed on 05/28/2022.

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