$Unique_ID{BRK03811} $Pretitle{} $Title{Hemorrhagic Telangiectasia, Hereditary} $Subject{Hemorrhagic Telangiectasia Hereditary Osler-Weber Rendu Syndrome Rendu-Osler-Weber Syndrome HHT von Willebrand Disease Calcinosis-Raynaud-Scleroderma-Telangiectasia Syndrome (CRST) Multiple Phlebectasias Spider Nevi Cherry Angiomas } $Volume{} $Log{} Copyright (C) 1986, 1988, 1989, National Organization for Rare Disorders, Inc. 285: Hemorrhagic Telangiectasia, Hereditary ** IMPORTANT ** It is possible the main title of the article (Hereditary Hemorrahagic Telangiectasia) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Osler-Weber Rendu Syndrome Rendu-Osler-Weber Syndrome HHT Information on the following diseases can be found in the Related Disorders section of this report: von Willebrand Disease Calcinosis-Raynaud-Scleroderma-Telangiectasia Syndrome (CRST) Multiple Phlebectasias Spider Nevi Cherry Angiomas General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Hereditary Hemorrhagic Telangiectasia (HHT or Osler-Weber-Rendu Syndrome) is a hereditary disorder characterized by blood vessel lesions (telangiectases) on the skin, mucous membranes and in many internal organs. Often, patients exhibit signs of anemia caused by bleeding of the telangiectases. Symptoms Individuals with Hereditary Hemorrhagic Telangiectasia develop red-to-violet lesions usually in the nasal mucous membranes (mucosa) and on the skin. The cheeks, ears, lips, and tongue are chiefly affected. Lesions also occur in the gastrointestinal tract and secondarily in other organs including the lungs, brain, spinal cord and liver. Bleeding can occur spontaneously or as a result of injury. Bleeding from the nose (epistaxis) and gastrointestinal tract becomes more severe with age and may lead to chronic anemia. Vein abnormalities (arteriovenous fistulae) may lead to a bluish discoloration of the skin (cyanosis), an increase in the number of red blood cells (polycythemia), clubbed fingers, and sometimes, stroke. While mortality as a result of this disorder appears to be less than ten percent, Hereditary Hemorrhagic Telangiectasia can cause many complications especially since it is often misdiagnosed or undiagnosed. Individuals with the disease and their families should be closely monitored by as physician familiar with the disease. Causes Hereditary Hemorrhagic Telangiectasia is a hereditary disorder, transferred as an autosomal dominant trait. (Human traits including the classic genetic diseases, are the product of the interaction of two genes for that condition, one received from the father and one from the mother. In dominant disorders, a single copy of the disease gene (received from either the mother or father) will be expressed "dominating" the normal gene and resulting in appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.) Symptoms of Hereditary Hemorrhagic Telangiectasia such as blood vessel lesions (telangiectases) in the lungs, brain, and liver, appear to be caused by abnormal connections between arteries and veins (arteriovenous fistulae). Telangiectases occur when the fistulae form to replace capillaries which normally connect small veins (venules) and small arteries (arterioles). The absence of intervening capillaries between the venules and arterioles are responsible for the profuse bleeding of the lesions. Affected Population Hereditary Hemorrhagic Telangiectasia can affect people of both sexes and all ages. The incidence in Europe has been reported to be 1 in 50,000. However, this might not be an accurate estimate in light of missed or improper diagnosis. Related Disorders Symptoms of the following disorders can be similar to those of Hereditary Hemorrhagic Telangiectasia. Comparisons may be useful for a differential diagnosis: von Willebrand Disease is a hereditary blood clotting disorder characterized by prolonged bleeding. Blood clotting is slowed due to a deficiency of the von Willebrand factor protein and factor VIII protein (the factor VIII complex). Also, platelets do not stick normally, causing excessively slow clotting time. Increased risk of excessive bleeding following surgery, dental procedures or injury occurs in patients with this disorder. With proper treatment and appropriate precautions, few patients become seriously handicapped by von Willebrand Disease. (For more information on this disorder, choose "von Willebrand" as your search term in the Rare Disease Database.) Caldcinosis-Raynaud-Sclerodactyly-Telangiectasisa Syndrome (CRST) is a combination of various symptoms, sand is usually due to Scleroderma. Calcinosis is marked by deposits of calcium salts in focal nodules in various body tissues other than the connective tissue which supports the various organs (parenchymatous viscera). Raynaud's Phenomenon involves a spasm of the arteries in the fingers causing sensations of numbness and cold. Sclerodactyly (acrosclerosis) is a form of Scleroderma which occurs with Raynaud's Phenomenon. Telangiectasia is a discolored enlargement of blood vessels visible in the skin. (For more information, choose "Scleroderma" and "Raynaud" as your search terms in the Rare Disease Database. Multiple Phlebectasias refers to enlargement of veins. Spider Nevi are small abnormally enlarged arteries visible in the skin with radiating branches resembling the legs of a spider. These arteries appear to have a dull red color. Cherry Angiomas (senile hemangiomas) consists of a red papule due to the weakening of the capillary wall, seen in many people over thirty years of age. These spots are also known as DeMorgan's or ruby spots. Therapies: Standard Treatment of Hereditary Hemorrhagic Telangiectasia) has been mainly concerned with preventing or stopping bleeding of the telangiectatic lesions and the removal or blockage of exceptionally large lesions or arteriovenous fistulae. Cauterization, whether electrical or with laser light, of telangiectases in the nasal mucosa may be of temporary benefit since new lesions can grow. Surgical removal of arteriovenous fistulae has been used in the past, but more recently occlusion by balloon embolotherapy has been found effective in the treatment of pulmonary arteriovenous fistulae. Nosebleed (epistaxis) can sometimes be controlled by applying a compress saturated with vasoconstrictors such as phenylephrine to the ruptured lesion. Blood transfusions or iron replacement therapy, either orally or by transfusing iron dextran, have been used to combat anemia. Gastrointestinal lesions that produce severe hemorrhage may require surgical removal. Therapies: Investigational Estrogen and progesterone therapy have been used experimentally to prevent bleeding. Recent findings indicate that estrogen is not effective while progesterone may hold some promise. This disease entry is based upon medical information available through June 1988. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Hereditary Hemorrhagic Telangiectasia, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 HHT Foundation International Inc. P.O. Box 8087 New Haven, CT 06530 Dr. Robert I White, Jr. Yale School of Medicine Department of Diagnostic Radiology 333 Cedar Street P.O. Box 3333 New Haven, CT 06510 NIH/National Heart, Lung and Blood Institute 9000 Rockville Pike Bethesda, MD 20892 (301) 496-4236 For information on genetics and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References MERCK MANUAL OF DIAGNOSIS AND THERAPY: Robert Berkow et al., eds.; American Medical Association, 1982. P. 1119.