$Unique_ID{BRK04342} $Pretitle{} $Title{Xeroderma Pigmentosum} $Subject{Xeroderma Pigmentosum Atrophoderma Pigmentosum Kaposi Disease Melanosis Lenticularis Progressiva XP } $Volume{} $Log{} Copyright (C) 1987, 1988, 1989 National Organization for Rare Disorders, Inc. 339: Xeroderma Pigmentosum ** IMPORTANT ** It is possible the main title of the article (Xeroderma Pigmentosum) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Atrophoderma Pigmentosum Kaposi Disease Melanosis Lenticularis Progressiva XP 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. Xeroderma Pigmentosum is a rare autosomal recessive hereditary disorder of the skin which begins during early childhood. It is characterized by a defect in the ability of certain connective tissue cells (fibroblasts) to repair skin damaged by ultraviolet rays. The skin of people with Xeroderma Pigmentosum is markedly hypersensitive to sunlight. Symptoms The first sign of Xeroderma Pigmentosum is usually freckling on parts of the skin that have been exposed to sunlight. Linear or star-shaped vascular lesions (telangiectasias) may appear next. Tumors made up of small blood vessels (capillary angiomas) may occur on ear margins, the tip of the nose, and on areas where mucous tissue joins skin such as the mouth. Weakened, degenerated (atrophic) areas of the skin appear smooth, dry, and light brown. Malignancies of the skin in people with this disorder may occur before age 5 through early adulthood. The face and skin of these children may resemble those of much older individuals. Growth retardation, dwarfism and mental retardation are also possible. Ocular symptoms may include abnormal intolerance to light (photophobia), excessive tears in the eyes (lacrimation), inflammation of the cornea (keratitis), clouding of the lens of the eye (opacities), and tumors of the eyelid or the cornea. Causes Xeroderma Pigmentosum (XP) is an autosomal recessive hereditary disorder. A deficit in the ability to repair the building blocks of genes (DNA), and the inability of certain types of connective tissue cells (fibroblasts) to repair damaged skin, cause the symptoms of this disorder. 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 recessive disorders, the condition does not appear unless a person inherits the same defective gene from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent and will be genetically normal. People with XP are markedly hypersensitive to the ultraviolet rays of sunlight which causes damage to DNA. Exposure to cancer causing agents (carcinogens) in the environment may also damage DNA. Indirectly, these agents may exacerbate XP in people who are genetically susceptible. Affected Population Xeroderma Pigmentosum may affect children of both sexes as early as the first year of life. Skin malignancies may appear before age 5. The disorder is more common in Japan and Egypt than in Europe and America. The disorder affects approximately 250,000 in the United States. Xeroderma Pigmentosum affects approximately one in one million people. Related Disorders There are many types of skin cancers, some of which are quite common. Malignant Melanoma of the skin is a malignant tumor of melanocyte origin. These tumors may appear in different sizes, shapes, and shades of color (mostly pigmented). The tumors have a variable ability for spreading to adjacent parts of the body, or through the blood and lymph circulation to other organs. Basal Cell Carcinomas (Rodent Ulcer) may appear as small, shiny, firm nodules; ulcerated, crusted lesions; flat, scar-like hardened plaques; or lesions difficult to differentiate from psoriasis or localized dermatitis. Squamous Cell Carcinomas are a common form of skin cancer that usually appears on sun-exposed areas of the skin, but may occur anywhere on the body. The lesions begin as a small red elevation or plaque with a scaly or crusted surface. They may then become nodular, sometimes with a warty surface. Therapies: Standard Total protection of the skin from sunlight in children with Xeroderma Pigmentosum can prevent additional lesions of the skin. Surgery, either extensive or limited, may be performed with limited success. Other treatment of Xeroderma Pigmentosum is symptomatic and supportive. Therapies: Investigational Application of an experimental cream containing catalase appears to hold promise for prevention of tumors in some children with Xeroderma Pigmentosum. Ointments containing vitamin A derivatives are also being investigated. Isotretinoin (Accutane) has been known to reduce the recurrence of tumors in people with Xeroderma Pigmentosum. However, the drug is very toxic and many people cannot tolerate side effects. T4 Endonuclease V.B. Liposome Encapsulated (T4N5) is a new orphan drug being used in the prevention of skin cancers and other skin abnormalities associated with patients diagnosed with xerodermas pigmentosum (XP). It is manufactured by Applied Genetics, Inc. 205 Buffalo Ave., Freeport, NY 11520. This disease entry is based upon medical information available through October 1989. 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 Xeroderma Pigmentosum, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Xeroderma Pigmentosum Registry c/o Department of Pathology Room 520, Medical Science Bldg. UMDNJ - New Jersey Medical School 100 Bergen Street Newark, NJ 07103 (201) 456-6255 The National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse Box AMS Bethesda, MD 20892 (301) 495-4484 The Skin Cancer Foundation 475 Park Avenue South New York, NY 10016 (212) 725-5176 NIH/National Cancer Institute 9000 Rockville Pike, Bldg. 31, Rm. 1A2A Bethesda, MD 20892 1-800-4-CANCER The National Cancer Institute has developed PDQ (Physician Data Query), a computerized database designed to give doctors quick and easy access to many types of information vital to treating patients with this and many other types of cancer. To gain access to this service, a doctor can contact the Cancer Information Service offices at 1-800-4-CANCER. Information specialists at this toll-free number can answer questions about cancer prevention, diagnosis, and treatment. For genetic information 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 XERODERMA PIGMENTOSUM, DEFECTIVE DNA REPAIR--AND SCHISTOSOMIASIS?: J. German; Annales de Genetique - Paris (1980: issue 23,2). Pp. 69-72. MICROINJECTION OF HUMAN CELL EXTRACTS CORRECTS XERODERMA PIGMENTOSUM DEFECT: A. J. de Jonge, et al.; EMBO Journal (1983: issue 2,5). Pp. 637-641.