Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder in which a limb may be affected by port wine stains (red-purple birthmarks involving blood vessels), varicose veins, and/or too much bone and soft tissue growth. The limb may be larger, longer, and/or warmer than normal. The cause is unknown.
Symptoms and severity of KTS vary for each patient. Symptoms can include bleeding from the affected limb, a skin infection, blood in the urine, or rectal/vaginal bleeding. You could experience pain in the limb, blood clots, anemia and seizures. Malformations of veins are a major feature of Klippel-Trenaunay syndrome. These abnormalities include varicose veins, which are swollen and twisted veins near the surface of the skin that often cause pain. Varicose veins usually occur on the sides of the upper legs and calves. Veins deep in the limbs can also be abnormal in people with Klippel-Trenaunay syndrome. Malformations of deep veins increase the risk of a type of blood clot called a deep vein thrombosis(DVT). If a DVT travels through the bloodstream and lodges in the lungs, it can cause a life-threatening blood clot known as a pulmonary embolism (PE).
Other complications of Klippel-Trenaunay syndrome can include a type of skin infection called cellulitis, swelling caused by a buildup of fluid (lymphedema), and internal bleeding from abnormal blood vessels. Less commonly, this condition is also associated with fusion of certain fingers or toes (syndactyly) or the presence of extra digits (polydactyly).
Seek treatment to alleviate pain and symptoms as necessary.
Klippel-Trenaunay syndrome can be caused by mutations in the PIK3CA gene. This gene provides instructions for making the p110 alpha (p110α) protein, which is one piece (subunit) of an enzyme called phosphatidylinositol 3-kinase (PI3K). PI3K plays a role in chemical signaling that is important for many cell activities, including cell growth and division (proliferation), movement (migration) of cells, and cell survival. These functions make PI3K important for the development of tissues throughout the body.
The PIK3CA gene mutations associated with Klippel-Trenaunay syndrome alter the p110α protein. The altered subunit makes PI3K abnormally active, which allows cells to grow and divide continuously. Increased cell proliferation leads to abnormal growth of the bones, soft tissues, and blood vessels.
Klippel-Trenaunay syndrome is one of several overgrowth syndromes, including megalencephaly-capillary malformation syndrome, that are caused by mutations in the PIK3CA gene. Together, these conditions are known as the PIK3CA-related overgrowth spectrum (PROS).
Because not everyone with Klippel-Trenaunay syndrome has a mutation in the PIK3CA gene, it is possible that mutations in unidentified genes may also cause this condition.
The goals of treatment are to reduce symptoms and reduce the risk of complications. Your health care provider will recommend the treatment option that is right for you. Medications and iron supplements may be prescribed, as well as compression stockings to alleviate pain and swelling. Surgery and other minimally invasive therapies are sometime necessary to treat KTS and its complications.
Klippel-Trenaunay Syndrome. (n.d.). Retrieved March 18, 2017, from https://my.clevelandclinic.org
Klippel-Trenaunay syndrome – Genetics Home Reference. (n.d.). Retrieved March 18, 2017, from https://ghr.nlm.nih.gov/condition/klippel-trenaunay-syndrome#