Klippel-Trenaunay Syndrome Symptoms & Causes

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Klippel-Trenaunay syndrome is an exceedingly rare vascular anomaly that is already present when your child is born. Doctors can sometimes see evidence of KTS in a prenatal ultrasound, and the capillary malformation (in the form of a "port-wine stain") is almost always apparent at the baby’s birth. KTS is equally common in boys and girls.

What causes Klippel-Trenaunay syndrome?
No one knows the precise cause of KTS. Some doctors think it's caused by a mutation that occurs before birth (but not one that's inherited) in the cells that form the lymphatic system, veins and other tissues. No known food, medication or activity during pregnancy can cause Klippel-Trenaunay.

Signs and symptoms of Klippel-Trenaunay syndrome
KTS often has three characteristic signs:

  • capillary malformation covering one or more limbs (arm or leg)
  • hypertrophy—or excessive growth—of a limb (usually a leg)
  • abnormal blood vessels, including veins, capillaries and lymphatic vessels (vessels that drain fluid that leaks from arteries and veins and return that fluid to the bloodstream)

What symptoms will my child have?
KTS affects different kids in different ways. One child may have a mild form of the syndrome with a small capillary malformation and one hand or foot slightly larger than the other. Another child may have a capillary malformation that runs from her chest down her leg, lots of swelling and one limb that is much larger than the other.

Here are some of the more common symptoms of Klippel-Trenaunay syndrome:

  • blood clots
  • cellulitis (infections in the skin)—your child may be more prone to infection because he is more likely to bleed easily as a result of the abnormal capillaries near the surface of his skin
  • anemia—due to blood loss because of easy bleeding
  • pain and heaviness of the affected limb—the pain can often be severe
  • difference in size between the affected and non-affected limb

Are there any other signs of KTS?
Some other signs of KTS include:

  • lymphatic abnormalities such as cysts and swelling
  • swollen veins

Long-term outlook

What is the long-term outlook for my child?
Because there’s no cure for KTS, we focus on managing your child’s symptoms. The long-term outlook for your child depends on a few factors:

  • the extent of the disease
  • the amount of hypertrophy in your child’s limb or limbs
  • the abnormal blood vessels’ response to therapy
  • the overall health of your child
  • your child's tolerance of specific medications, procedures or therapies
  • new developments in treatment

Every child is unique, and your care team will work with you to develop a treatment plan for Klippel-Trenaunay syndrome [MSP1] that works for your family.

Does KTS get better?
No. KTS is a progressive condition, which means that it will grow as your child grows. That said, many kids—especially those with mild cases of KTS—go on to live normal, healthy lives.

What do we do after treatment is over?
Depending on the severity of your child’s condition, your doctor may recommend a series of follow-up visits to check for complications and make sure that we’re managing the KTS effectively.

A typical follow-up visit may include some or all of the following:

  • a physical exam
  • laboratory testing
  • imaging scans (e.g., MRI, CT scans, ultrasound)
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