Klippel-Trenaunay (klih-PEL tray-no-NAY) syndrome ― also called KTS ― is a rare disorder found at birth (congenital) involving abnormal development of blood vessels, soft tissues (such as skin and muscles), bones, and the lymphatic system. The main features include a red birthmark (port-wine stain), overgrowth of tissues and bones, and vein malformations with or without lymphatic abnormalities.

Although there is no cure for KTS, the goal is to manage symptoms and prevent complications.

People who have Klippel-Trenaunay syndrome may have the following features, which can range from mild to more extensive:

• Port-wine stain. This pink to reddish-purple birthmark is caused by extra tiny blood vessels (capillaries) in the top layer of skin. The birthmark usually covers part of one leg, but can involve any portion of the skin, and may get darker or lighter with age.
• Vein malformations. These include swollen, twisted veins (varicose veins) usually on the surface of the legs. Deeper abnormal veins in the arms, legs, abdomen and pelvis can occur. There may be spongy tissue filled with small veins in or under the skin. Venous abnormalities may become more prominent with age.
• Overgrowth of bones and soft tissue. This begins in infancy and is usually limited to one leg, but it can occur in an arm or, rarely, in the trunk or face. This overgrowth of bone and tissue creates a larger and longer extremity. Rarely, fusion of fingers or toes, or having extra fingers or toes occurs.
• Lymphatic system abnormalities. The lymphatic system — part of the immune system that protects against infection and disease and transports lymphatic fluid — can be abnormal. Extra lymphatic vessels can be present that don't work properly and can lead to leakage and swelling.
• Other conditions. KTS can also include cataracts, glaucoma, hip dislocation at birth and blood-clotting problems.

When to see a doctor

Klippel-Trenaunay syndrome is usually identified at birth. It's important to get a prompt, accurate diagnosis and appropriate care to treat symptoms and prevent complications.

Klippel-Trenaunay syndrome is a genetic condition. It involves genetic changes (mutations) most commonly in the PIK3CA gene. These genetic changes are responsible for development of tissues in the body, resulting in overgrowth.

KTS is not usually inherited. The gene mutations occur randomly during cell division in early development before birth.

Family history doesn't seem to be a risk factor, so it's unlikely that parents of one child with Klippel-Trenaunay syndrome will have another child with the disorder, even if one of the parents has KTS.

Complications of Klippel-Trenaunay syndrome can result from abnormal development of blood vessels, soft tissues, bones and the lymphatic system. These can include:

• Port-wine stain complications. Some areas of the port-wine stain may thicken over time and may form blisters (blebs) that are prone to bleeding and infections.
• Vein malformations. Varicose veins can cause major pain and skin ulcers due to poor circulation. Deeper abnormal veins can increase the risk of blood clots (deep vein thrombosis) and cause a life-threatening condition called pulmonary embolism if they dislodge and travel to the lungs. Venous malformations in the pelvis and abdominal organs can cause internal bleeding. Superficial veins can develop less serious but painful clots and inflammation (superficial thrombophlebitis).
• Overgrowth of bones and soft tissue. Overgrowth of bone and tissue can cause pain, a feeling of heaviness, enlargement of the limb and problems with movement. Overgrowth that causes one leg to be longer than the other can cause problems with walking and may lead to hip and back problems.
• Lymphatic system abnormalities. An abnormality can cause fluid buildup and swelling in the tissues of the arms or legs (lymphedema), skin breakdown and skin ulcers, the development of small masses (lymphatic cysts) in the spleen, leakage of lymphatic fluid, or infection of the layer under the skin (cellulitis).
• Chronic pain. Pain can be a common problem that results from complications such as infections, swelling or vein problems.

Diagnosis of Klippel-Trenaunay syndrome begins with a physical exam. Referral to a vascular malformations specialist is helpful for evaluation and treatment recommendations. During the evaluation your doctor:

• Asks questions about your family and medical history
• Does an exam to look for swelling, varicose veins and port-wine stains
• Visually evaluates growth of bones and soft tissues

Several diagnostic tests can help your doctor evaluate and identify the type and severity of the condition and help determine treatment. Some tests include:

• Duplex scanning. This test uses high-frequency sound waves to create detailed images of blood vessels.
• Scanogram. Also called scanner photography, this X-ray technique helps to see images of bones and measure their lengths.
• MRI and magnetic resonance angiography. These procedures help differentiate between bone, fat, muscle and blood vessels.
• CT scan. A CT scan creates 3-D images of the body that helps look for blood clots in veins.
• Contrast venography. This procedure involves injecting a dye into veins and taking X-rays that can reveal abnormal veins, blockages or blood clots.

Although there's no cure for Klippel-Trenaunay syndrome, your doctor can help you manage symptoms and prevent complications.

Because KTS may affect many systems in the body, your health care team may include specialists in vascular medicine and surgery, skin diseases (dermatology), interventional radiology, orthopedic surgery, physical therapy and rehabilitation, and other areas as needed.

You and your doctor can work together to determine which of the following treatments are most appropriate for you. Treatments may include:

• Compression therapy. Bandages or elastic garments are wrapped around affected limbs to help prevent swelling, problems with varicose veins and skin ulcers. These bandages or elastic garments often need to be custom-fit. Intermittent pneumatic compression devices — leg or arm sleeves that automatically inflate and deflate at set intervals — may be used.
• Physical therapy. Massage, compression and limb movement as appropriate may help relieve lymphedema in arms or legs and swelling of the blood vessels.
• Orthopedic devices. These may include orthopedic shoes or shoe inserts to compensate for differences in leg length.
• Epiphysiodesis (ep-ih-fiz-e-OD-uh-sis). This is an orthopedic surgical procedure that effectively can stop length overgrowth of the lower limb.
• Embolization. This procedure, performed through small catheters placed into the veins or arteries, blocks blood flow to certain blood vessels.
• Laser therapy. This procedure may be used to lighten port-wine stains and to treat early blebs on the skin.
• Laser or radiofrequency ablation of veins. This minimally invasive procedure is used to close off abnormal veins.
• Sclerotherapy. A solution is injected into a vein, which creates scar tissue that helps close the vein.
• Surgery. In some cases, surgical removal or reconstruction of affected veins, removal of excess tissue, and correction of the overgrowth of bone may be beneficial.
• Medication. Early research indicates that a drug called sirolimus (Rapamune) may help to treat symptomatic complex vascular malformations, but it may have significant side effects and more studies are needed.

In addition, treatment may be needed for complications such as bleeding, pain, infection, blood clots or skin ulcers.

Strategies to help manage Klippel-Trenaunay syndrome symptoms include:

• Keep appointments. Regularly scheduled appointments can help your doctor identify and address problems early. Ask your doctor about a schedule of appointments appropriate for you.
• Use orthopedic shoes, if recommended. Orthopedic shoes or shoe inserts may improve your physical function.
• Follow your doctor's recommendations on physical activity. Encouraging use of affected limbs as appropriate may help relieve lymphedema and swelling of the blood vessels.
• Elevate affected limbs. When possible, raising your leg or other affected limb can help reduce lymphedema.
• Notify your doctor of changes. Work with your doctor to manage your symptoms and prevent complications. Contact your doctor if you have symptoms of blood clots or an infection or if you experience increased pain or swelling.

Living with Klippel-Trenaunay syndrome can be a challenge. Support and advocacy groups can provide a connection with other people who have KTS. The K-T Support Group and other organizations provide educational materials, resources and information about support groups. Ask your doctor if there is a local support group in your area.

Talking with a psychologist, psychiatrist or other mental health professional may also be helpful to many people with KTS.

Most cases of Klippel-Trenaunay syndrome are found at birth. So if the doctor suspects that your child has this syndrome, diagnostic tests and treatment will likely begin before your child leaves the hospital.

Your child's doctor will look for developmental problems at regular checkups and give you the opportunity to discuss any concerns. It's important to take your child to all regularly scheduled well-baby visits and annual appointments.

Here's some information to help you prepare for the appointment.

What you can do

If your doctor believes your child shows signs of KTS, basic question to ask include:

• What diagnostic tests will be needed?
• When will I get the results of the tests?
• What specialists might be needed?
• What medical conditions related to this syndrome need to be addressed right now?
• How will you help me monitor my child's health and development?
• Can you suggest educational materials and local support services regarding this syndrome?

What to expect from your doctor

Your child's doctor will ask you a number of questions. Be ready to answer them to reserve time to go over points you want to focus on. The doctor may ask:

• What symptoms does your child have that concern you?
• Has your child had any procedures or treatments for these symptoms?
• Has your child had any previous difficulty with infections or blood clots?
• Did you have any problems with your pregnancy or your child's birth?
• Can you tell me about your family's medical history?
• Is your child having any problems dealing with family, social activities or school?