$Unique_ID{BRK04340} $Pretitle{} $Title{X-linked Juvenile Retinoschisis} $Subject{X-linked Juvenile Retinoschisis RS Juvenile Retinoschisis X-linked Retinoschisis Familial Foveal Retinoschisis Macular Degeneration } $Volume{} $Log{} Copyright (C) 1991 National Organization for Rare Disorders, Inc. 797: X-linked Juvenile Retinoschisis ** IMPORTANT ** It is possible that the main title of the article (X-linked Juvenile Retinoschisis) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms RS Juvenile Retinoschisis X-linked Retinoschisis Information on the following disorders can be found in the Related Disorders section of this report: Familial Foveal Retinoschisis Macular Degeneration 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. X-linked Juvenile Retinoschisis (RS) is a genetic disorder affecting males. Major symptoms may include poor eyesight and degeneration of the retina. The retina consists of membrane layers in the eye that receive visual images after passing through the lens. It is composed of supportive and protective structures, nervous system components and layers including "rods" and "cones". RS is due to splitting of the retina which in turn causes slow, progressive loss of parts of the fields of vision corresponding to the areas of the retina which have become split. Often, RS is associated with the development of cysts (sac-like blisters) in the retina. Symptoms Symptoms of X-linked Juvenile Retinoschisis (RS) may include poor eyesight, detachment of all or part of the retina from the rest of the eye, and eventually complete retinal atrophy (wasting away) with hardening of the choroid (the membrane between the white part of the eye and the retina). The patient may develop cysts in the macula (an oval area of the retina) and other areas of the retina. The cysts lead to splits within the retina. The cystic manifestations may also appear in other family members. Bleeding within the eye may occur. Problems with vision are usually mild up until the age of 40 or 50, after which the condition may slowly worsen. Causes X-linked Juvenile Retinoschisis (RS) is inherited as an X-linked recessive trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. 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 only have 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. Affected Population X-linked Juvenile Retinoschisis (RS) is a rare disorder present at birth. The disorder affects males. Men of Finnish heritage are affected more often than those of other heritages. Until the age of 40 or 50, visual handicap is usually mild. Related Disorders Symptoms of the following disorders can be similar to those of X-linked Juvenile Retinoschisis (RS). Familial Foveal Retinoschisis is another type of Juvenile Retinoschisis which involves splitting of tissue within the fovea (the center of the macula and the area of clearest vision) of the retina. It is very similar to X- linked Juvenile RS, but the changes in the retina are not as severe. A completely blind area (scotoma), with a sharp edge in the area where splitting occurs, is evident in the patient's visual field. Foveal RS can also occur in patients with X-linked Juvenile RS. (For more information on this disorder, choose "retinoschisis" as your search term in the Rare Disease Database). Macular Degeneration (MD) is characterized by a gradual decrease of vision. It is inherited as a dominant trait. MD can be a static condition for many years, but then becomes slowly progressive with age. Central vision is impaired or absent in MD while peripheral vision remains normal. A vision disturbance in which shapes seem distorted or changing (metamorphopsia) can occur. An area of depressed vision within the visual field surrounded by an area of normal vision (central scotoma) is also symptomatic of this disorder. Polymorphic Macular Degeneration (PMD) is a dominant hereditary vision disorder which includes Best Disease and Sorsby Disease. PMD usually affects the macular region in both eyes. In Sorsby Disease swelling (edema), hemorrhage, and cyst formation are noted. The cysts may vary in size and appearance. The cystic manifestations may also appear in other family members. In advanced stages considerable atrophy occurs. In Best Disease, changes in the macular region, as well as other areas of the eye, may be noted before visual impairment occurs. The macular area may show a yellow mass resembling the yolk of an egg. This lesion may possibly be present at birth. Deep irregular pigmentation inside the eye may develop later. (For more information on these disorders, choose "Macular Degeneration" as your search term in the Rare Disease Database). Therapies: Standard Diagnosis of X-linked Juvenile Retinoschisis (RS) can be made by an ophthalmologist through various tests: Measuring visual acuity with the Snellen chart, the patient is asked to look through a pinhole to determine where on the retina a lesion may exist. Ultrasonography or ultrasound may show abnormalities when a hemorrhage has occurred in the eye. A recording of the electrical impulses emitted by the retina in response to light stimulus (electroretinogram; ERG) can be made. ERG's can indicate abnormalities of the retina. A Visual Evoked Response (VER) measures slow electric potentials from the brain cortex in response to light stimulation. The VER depends on the integrity of the entire visual system from the cornea to the occipital part of the brain's cortex. The VER can detect a malfunction of the macular portion of the retina which controls central vision. A photographic picture made with an ophthalmoscope of the back portion of the inside of the eyeball (fundus) is another way to gather information about the retina. When bleeding occurs within the eyeball, keeping the eye still helps to reduce damage. Later, treatment with laser or cold (cryotherapy) can be applied to close off the damaged area of the retina. It is imperative to avoid jarring the head or inflicting injury to the eye to slow down the degenerative process of RS. Genetic counseling may be of benefit for patients with X-linked Juvenile Retinoschisis and their families. Other treatment is symptomatic and supportive. Therapies: Investigational Sulfur Hexafluoride is an experimental medical device for treatment of patients with detached retinas. For information about clinical trials being conducted, please contact: Airco Welding Products 575 Mountain Ave. Murray Hill, NY 07974 This disease entry is based upon medical information available through June 1991. 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 X-Linked Juvenile Retinoschisis, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 NIH/National Eye Institute 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5248 Association for Macular Disease, Inc. 210 East 64th Street New York, NY 10021 (212) 605-3719 For genetic information and genetic counseling referrals: 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 MENDELIAN INHERITANCE IN MAN, 8th Ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. Pp. 1173, 1373, 1375. AUTOSOMAL JUVENILE RETINOSCHISIS WITHOUT FOVEAL RETINOSCHISIS. S. Hara and K. Yamaguchi; Br J Ophthalmol (June 1989; issue 73 (6)). Pp. 470-473. LINKAGE RELATIONSHIPS AND GENE ORDER AROUND THE LOCUS FOR X-LINKED RETINOSCHISIS. T. Alitalo, et al.; Am J Hum Genet (Oct 1988; issue 43 (4)). Pp. 476-483. USE OF LINKED DNA PROBES FOR CARRIER DETECTION AND DIAGNOSIS OF X-LINKED JUVENILE RETINOSCHISIS. N. Dahl and U. Pettersson; Arch Ophthalmol (Oct 1988; issue 106 (10)). Pp. 1414-1416.