Klippel-Trenaunay syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 30, 2016
StartDiseasesKlippel-Trenaunay syndrome

Klippel-Trenaunay syndrome or KTS is a rare disease that presents as abnormalities in the patient’s capillaries, bone, soft tissue, and lymphatic system. It affects males and females equally and is found around the world. It affects about 1 in 100,000 people internationally.


Definition & Facts

KTS is a congenital disorder, which means that people are born with it. It is most often seen in the lower limbs and not so much in the trunk or the arms. Most people with Klippel-Trenaunay syndrome do not struggle with intellectual disability.

Symptoms & Complaints

People with this condition are born with a port-wine stain somewhere on their limb. A port-wine stain is is an overgrowth of tiny blood vessels just under the skin. The stain can be pink or deep reddish purple, and often becomes lighter or darker as the patient ages. Sometimes, port-wine stains have tiny blisters that break open and bleed.

Bones and soft tissue can also grow abnormally in a patient with Klippel-Trenaunay syndrome. Usually, this abnormal growth is only seen in one limb which is usually a leg. This can make moving around difficult, for the leg can be longer or heavier than the other and cause the patient pain. In other cases, the affected leg can be shorter or lighter than the normal leg.

People with KTS suffer from varicose veins, which are distended, worm-like veins that are sometimes painful. They’re usually found in the upper legs and in the patient’s calves.

Deep veins can also be malformed in patients with KTS and can put them at risk for deep vein thrombosis. This is a blood clot that develops in the vein. If it breaks off, it can travel to the lungs and cause a pulmonary embolism, which can be fatal.

The abnormal veins can also rupture and cause internal hemorrhaging. The patient may see blood in their urine and vaginal bleeding or rectal bleeding. They may also suffer from anemia.

Another symptom of Klippel-Trenaunay syndrome is cellulitis, which is an infection of the skin, and lymphedema in which there is an accumulation of lymph fluid. Some people with KTS are born with fused fingers (syndactyly) or too many fingers (polydactyly) and may suffer from seizures. They sometimes have abnormal fat deposits in their bodies.


Doctors believe that one cause of Klippel-Trenaunay syndrome is a mutation in a gene called PIK3CA. This gene holds the blueprint for making a protein called P110alpha, which is a component of an enzyme called phosphatidylinositol 3-kinase, or PI3K. This enzyme is important in the growth, division, migration and survival of cells that make up tissues found all over the body.

The mutation in the PIK3CA gene makes the enzyme overactive, and this causes the cells of the bones, blood vessels and soft tissues to grow and divide abnormally and continuously. However, not every KTS patient has the PIK3CA mutation. Scientists are trying to find other genes that can lead to the disorder.

Klippel-Trenaunay syndrome arises from somatic mutations, which means it can appear in a person who has no family history of KTS. The mutations in the gene aren’t inherited but occur before birth. During fetal development, one cell becomes abnormal, and the abnormality is replicated in some of the cells that result from its division.

Diagnosis & Tests

Doctors diagnose Klippel-Trenaunay syndrome by physically examining the patient and ordering computed tomography (CT) scans and magnetic resonance imaging (MRI) scans to produce images of abnormal tissues, bones, and blood vessels.

Treatment & Therapy

There are several treatments and therapies for Klippel-Trenaunay syndrome. They are tailored to the particular needs of the individual KTS patient. In many cases, the patient is fitted with a compression stocking to ease the swelling and discomfort of an affected limb. Surgery might be done to prevent complications of the condition. Surgeries include:

  • Venous ablation. During venous ablation, the doctor makes a tiny incision in the skin to remove a damaged vein. Sometimes the vein isn’t removed but tied off. This is called ligation. Both of these procedures keep venous blood from pooling in the limb.
  • Laser therapy. Doctors use lasers to reduce the appearance of a port-wine stain and to shrink varicose veins. Lasers can be used with both ablation and sclerotherapy. Most patients need a few sessions of laser therapy scheduled a month and a half apart.
  • Sclerotherapy eases the pain of varicose veins and prevents ulcers and hemorrhaging. During sclerotherapy, the doctor injects a sclerosing agent into the vein, which causes it to collapse. The body then absorbs the destroyed vein. Sometimes, the agent is mixed with a special type of foam that clears the blood out of the vein. This makes the sclerosing agent more effective.
  • Endovenous thermal ablation. This technique uses high frequency radio waves or laser to close up a problematic vein. The difference between regular ablation is that the vein is left in the limb, which results in less pain and bleeding and a shorter recovery period for the patient.

In addition, a surgeon may need to remove part of the patient’s colon if it continually bleeds. Surgery may also be necessary to stop bleeding in the bladder through laser therapy. Certain procedures may be performed to change the length of the limbs and appendages. An operation on the knee called epiphysiodesis can make the legs the same length. In addition, leg lifts may be opted for in order to prevent a curvature of the spine called scoliosis. If a patient is at risk for blood clots, the doctor may prescribe an anticoagulant such as heparin.

Prevention & Prophylaxis

As of 2016, there is no way to prevent Klippel-Trenaunay syndrome. The chief complaint of most patients is an enlarged leg, and the compression stocking can be effective in preventing blood from pooling and the skin in the area from ulcerating. Most patients do not need surgery.