Klippel-Trenaunay Syndrome

Klippel-Trenaunay syndrome is a rare birth defect (congenital) resulting into an abnormal development of blood vessels, soft tissues, bones or the lymphatic system. Under rare conditions, fusion of fingers or toes or formation of extra fingers or toes, may also occur. The disorder can be characterized by three main features: a reddish - purple birthmark called a port-wine stain, abnormal growth of soft tissues and bones, and vein malformations.

These birthmarks occur due to swelling of small blood vessels near the surface of the skin. Port-wine stains are usually flat and can vary from pale pink to deep maroon in color. The port-wine stains usually covers a part of one limb. The affected area may become lighter or darker with age.

The disease might be accompanied by malformations of deep veins which increase the risk of a type of clot called deep vein thrombosis (DVT). If DVT travels through the bloodstream and lodges into the lungs, it can cause a life-threatening clot known as a pulmonary embolism (PE).

People suffering from Klippel-Trenaunay syndrome may show the following symptoms, which can range from mild to severe:

• Appearance of port-wine stain: The stain is caused due to swelling of the blood capillaries which results into formation of a pink to reddish-purple birthmark. In most cases, the birthmark usually covers a part of one leg, or sometimes one arm, and may get darker or lighter with age of the patient. Some areas may get prone to bleeding and infections.
• Vein malformations- The malformations can be seen as swollen, twisted veins (varicose veins) usually on the surface of the legs, which causes pain and and may lead to skin ulcers as a result of poor circulation. Spongy tissues filled with small veins in/under the skin may lead to bleeding, infection or inflammation.
• Overgrowth of bones and soft tissue- The condition is usually limited to one leg and begins at an infant stage but may also affect an arm/trunk. The overgrowth can cause pain, lethargy and may restrict the movement. 
• Lymphatic system abnormalities- The lymphatic system is an important part of our immune system, which is responsible for inhibition of infection and diseases that affect our body. Lymphedema can occur as a result of fluid buildup and swelling in the tissues of the arms or legs. The condition may also lead to cellulitis and lymph clots.

Although the exact cause of Klippel-Trenaunay syndrome is not known, it is believed that it can occur due to certain mutations in the genetic makeup of the individual. The birth defect affects men and women equally, and is not limited to any racial group.

Klippel-Trenaunay Syndrome is diagnosed on the basis of appearance of physical signs and symptoms of the disease like port wine stain.