$Unique_ID{BRK04305} $Pretitle{} $Title{Usher's Syndrome} $Subject{Usher's Syndrome Hereditary Deafness-Retinitis Pigmentosa Retinitis Pigmentosa and Congenital Deafness Type I Usher Type II Usher Type III Usher Type IV Usher Retinitis Pigmentosa Hallgren Syndrome Alstrom Syndrome Rubella} $Volume{} $Log{} Copyright (C) 1989, 1990 National Organization for Rare Disorders, Inc. 529: Usher's Syndrome ** IMPORTANT ** It is possible the main title of the article (Usher Syndrome) is not the name you expected. Please check the SYNONYMS listing on the next page to find alternate names and disorder subdivisions covered by this article. Synonyms Hereditary Deafness-Retinitis Pigmentosa Retinitis Pigmentosa and Congenital Deafness DISORDER SUBDIVISIONS: Type I Usher Type II Usher Type III Usher Type IV Usher Information on the following diseases can be found in the Related Disorders section of this report: Retinitis Pigmentosa Hallgren Syndrome Alstrom Syndrome Rubella 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. Usher's Syndrome is a genetic disorder primarily characterized by deafness accompanied by Retinitis Pigmentosa, a disorder that causes progressive loss of vision. The age at which the disorder appears as well as severity of symptoms distinguishes the four types of Usher's Syndrome. Symptoms Usher's Syndrome is characterized by nerve deafness (sensorineural hearing loss) as well as Retinitis Pigmentosa, a disorder that causes degeneration of the retina leading to progressive loss of vision. The nerve deafness may be complete or mild, and usually does not progress. The Retinitis Pigmentosa can begin during childhood or later in life. Studies show that clear central vision may be maintained for many years even while side (peripheral) vision decreases. In some cases, these symptoms may be accompanied by mental deficiencies, psychosis, disturbances in walking related to inner ear problems, or cataracts. Type I Usher's Syndrome is characterized by complete hearing loss at birth, vision problems beginning at approximately the age of ten, development of night blindness at approximately twenty years of age, and progressive loss of peripheral vision. Type II Usher's Syndrome is identified by moderate to complete hearing loss at birth, and the onset of Retinitis Pigmentosa during the late teens or early twenties. Night blindness usually begins during the late twenties or thirties. Type III Usher's Syndrome usually begins at puberty with progressive hearing loss. Retinitis Pigmentosa begins much later in life. Type IV Usher's Syndrome predominately affects males and is also characterized by hearing loss and progressive vision disturbances. This is an extremely rare form of Usher's Syndrome and is thought to be inherited as an X-Linked trait. Causes Usher's Syndrome is inherited as an autosomal recessive trait in types I, II and III. Type IV Usher's Syndrome is thought to be inherited as an X-Linked recessive 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 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. X-linked recessive disorders are conditions which are coded on the X chromosome. Females have two X chromosomes, but males have one X chromosome and one Y chromosome. Therefore in females, disease traits on the X chromosome can be masked by the normal gene on the other X chromosome. Since males have only one X chromosome, if they inherit a gene for a disease present on the X, it will be expressed. Men with X-linked disorders transmit the gene to all their daughters, who are carriers, but never to their sons. Women who are carriers of an X-linked disorder have a fifty percent risk of transmitting the carrier condition to their daughters, and a fifty percent risk of transmitting the disease to their sons. The exact reason for the hearing and vision loss in Usher's Syndrome is not well understood. Persons with Usher Syndrome may have a hypersensitivity to compounds which could damage chromosomal components known as DNA. This suggests a defective DNA repair mechanism. Immune system disturbances are also thought to be associated with Usher Syndrome, although the exact process is not well understood. In 1989 researchers discovered the chromosome marker for Type II Usher Syndrome. This is expected to lead to the isolation of the genes that cause this disorder, identification of gene carriers, and perhaps, prenatal tests. Affected Population Usher's Syndrome affects approximately five to ten in 100,000 people worldwide. Higher than normal numbers of people with Usher's Syndrome have been found among Jewish people in Berlin, Germany; French Canadians of Louisiana; Argentineans of Spanish descent; and Nigerian Africans. Related Disorders Symptoms of the following disorders can be similar to those of Usher Syndrome. Comparisons may be useful for a differential diagnosis: Hallgren Syndrome is also known as Graefe-Sjogren Syndrome. Deafness at birth is accompanied by progressive vision impairment including nystagmus and cataracts. Additional symptoms are psychomotor retardation, vestibulocerebellar ataxia, mental deficiency and psychosis. Alstrom Syndrome is an inherited disorder characterized by retinal degeneration with nystagmus and loss of central vision. This disorder is associated with obesity in childhood. Nerve deafness and Diabetes Mellitus tend to develop after the age of ten years. Rubella is more commonly known as German measles. This acute viral disorder is of concern when contracted during the first three months of pregnancy because it can cause fetal abnormalities. These abnormalities may include hearing loss and/or vision disturbances as well as developmental malformations. (For more information on this disorder, choose "Measles" as your search term in the Rare Disease Database). The following disorder is associated with Usher's Syndrome as a symptom complex. It is not necessary for a differential diagnosis because it may start years after onset of nerve deafness. Retinitis Pigmentosa (RP) is one of a group of inherited eye diseases causing degeneration of the retina. When the retina degenerates, as in RP, the vision decreases and may occasionally be lost. Retinitis Pigmentosa may be associated with other symptoms such as central nervous system disorders, metabolic disorders and even chromosomal abnormalities such as Turner's Syndrome. (For more information on these disorders, choose "RP" and "Turner" as your search terms in the Rare Disease Database.) Therapies: Standard Treatment of Usher's Syndrome is symptomatic and supportive. Agencies which provide services to individuals with hearing and vision loss can be helpful. Surgery to remove cataracts in conjunction with intraocular lens implantation may improve vision problems in some cases. Genetic counseling is recommended for patients and their families. It is important to identify as early as possible whether a deaf child may have Usher's Syndrome. If vision loss occurs later in life, teaching a child sign language may have little value as a communication aid during adulthood. Therefore, educational methods and options should be chosen carefully during school years. Therapies: Investigational Scientists are currently studying Usher's Syndrome to identify the location of the defective gene and a chromosomal marker. Once this gene is identified, researchers may then be able to develop effective treatment. This disease entry is based upon medical information available through May 1990. 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 Usher's Syndrome, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 RP Foundation Fighting Blindness 1401 Mt. Royal Avenue Baltimore, MD 21217 (800) 638-2300 (301) 225-9400 Alexander Graham Bell Association for the Deaf 3417 Volta, NW Washington, DC 20007 (202) 337-5220 For Trained Hearing Dogs: American Humane Association P.O. Box 1266 Denver, CO 80201 Deafness Research Foundation 55 East 34th Street New York, NY 10016 (212) 684-6556 National Information Center on Deafness Gallaudet College Kendall Green Washington, DC 20002 voice & tdd phone (202) 651-5109 American Society for Deaf Children 814 Thayer Avenue Silver Spring, MD 20910 (301) 585-5400 Voice/TTY NIH/National Eye Institute 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5248 NIH/National Institute of Deafness & Other Communication Disorders (NIDCD) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5751 National Federation of the Blind 1800 Johnson Street Baltimore, MD 21230 (301) 659-9314 1-800-638-7518 American Council of the Blind, Inc. (ACB) 1155 - 15th St., NW, Suite 720 Washington, D.C. 20005 (202) 467-5081 (800) 424-8666 American Foundation for the Blind (AFB) 15 W. 16th St. New York, NY 10011 (212) 620-2000 Regional offices: Atlanta, GA (404) 525-2303 Chicago, IL (312) 245-9961 Dallas, TX (214) 352-7222 San Francisco, CA (415) 392-4845 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 This Rare Disease Database entry is based upon outlines prepared by medical and dental students (1984-1986) at the Medical College of Virginia for their course in human genetics, and the following articles: MENDELIAN INHERITANCE IN MAN, 7th ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. Pp. 1293, 1450. FIGHTING BLINDNESS NEWS, RP Foundation Fighting Blindness; Winter 1987- 1988 Newsletter. Pp. 2-4. RADIATION SENSITIVITY OF FIBROBLAST STRAINS FROM PATIENTS WITH USHER'S SYNDROME, DUCHENNE MUSCULAR DYSTROPHY, AND HUNTINGTON'S DISEASE: J. Nove, et al.; Mutat Res (July 1987, issue 184(1) ). Pp. 29-38. USHER'S SYNDROME. OPHTHALMIC AND NEURO-OTOLOGIC FINDINGS SUGGESTING GENETIC HETEROGENEITY: G.A. Fishman, et al.; Arch Ophthalmol (September 1983, issue 101(9) ). Pp. 1367-74. CATARACT EXTRACTION AND INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH RETINITIS PIGMENTOSA OR USHER'S SYNDROME: D.A. Newsome, et al.; Arch Ophthalmol (June 1986, issue 104(6)). Pp. 852-854.