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Usher’s Syndrome Usher syndrome is the most common condition that affects both hearing and vision. A syndrome is a disease or disorder that has more than one feature or symptom. The major symptoms of Usher syndrome are hearing loss (congenital nerve deafness) and an eye disorder called retinitis pigmentosa, or RP. RP causes night-blindness and a loss of peripheral vision (side vision) through the progressive degeneration of the retina. As RP progresses, the field of vision narrows and a condition known as “tunnel vision”—until only central vision (the ability to see straight ahead) remains. Many people with Usher syndrome also have severe balance problems. About 3-6 percent of all deaf children and perhaps an equal number of hard-of-hearing children have Usher Syndrome (US) which is more then one genetic condition. What causes Usher’s Syndrome Usher is inherited and passes from parent to child through genes. It is an autosomal recessive trait. The term autosomal means that the mutated gene is not located on either of the chromosomes that determine a person’s sex. In other words, both males and females can have the disorder and can pass it along to a child. The word recessive means that, to have Usher syndrome, a person must receive a mutated form of the Usher syndrome gene from each parent. If a child has a mutation in one Usher syndrome gene but the other gene is normal, he or she is predicted to have normal vision and hearing. In developed countries such as the United States, about four babies in every 100,000 births have Usher syndrome. Retinitis Pigmentosa (RP) affects the sensory cells in the retina, which is the layer lining the inside of the eye. The retina itself is made up of several layers of interconnecting cells, two of which are called rods and cones. These cells gradually deteriorate and die in RP and many other so-called retinal dystrophies. The 150 million can see in dim light. Rods are spread throughout the retina except in the fovea, which is the spot in the center back directly behind the pupil. The fovea contains only cones which control day vision and are important for seeing fine details and color. Surrounding the fovea is the macula which is rich in cones, but cones are also scattered throughout the rest of the retina. About 7 million cones are present in each retina. By the time the cones deteriorate, doctors can see distinctive changes when they look at the retina. These include pigment dispersion, which means that some parts appear lighter than others, followed by "bone spicules" which are little jagged spots. The blood vessels become narrow or "attenuated" and the optic disc (nerve) develops a pale and waxy yellow appearance. All of these changes get worse as the disease progresses. Sensorineural hearing loss occurs when parts of the inner ear (including the cochlea and/or auditory nerve) do not work correctly. The amount (or degree) of hearing loss can be described by measuring the hearing threshold (the sound level that a person can just barely hear) in decibels (dB). The greater a person's dB hearing level, the louder the sound must be to just barely be heard. People with Usher’s syndrome generally have moderate, severe, or profound depending on the type (I, II, or III) Diagnosis Researchers are currently trying to identify all of the genes that cause Usher’s Syndrome and determine the function of those genes. This research will lead to improved genetic counseling and early diagnosis, and may eventually expand treatment options. Because Usher syndrome affects hearing, balance, and vision, diagnosis of the disorder usually includes the evaluation of all three senses. Evaluation of the eyes may include a visual field test to measure a person’s peripheral vision, an electroretinogram (ERG) to measure the electrical response of the eye’s lightsensitive cells, and a retinal examination to observe the retina and other structures in the back of the eye. loud sounds at a range of frequencies need to be before a person can hear them. An electronystagmogram (ENG) measures involuntary eye movements that could signify a balance problem. Early diagnosis of Usher syndrome is very important. The earlier that parents know if their child has Usher syndrome, the sooner that child can begin special educational training programs to manage the loss of hearing and vision. Characteristics of the three types: Type 1 Profound deafness in both ears from birth Type2 Type 3 Moderate to severe hearing loss from birth Normal at birth progressive loss in childhood or early teens Vision Decreased night vision before age 10 Decreased night vision begins in late childhood or teens Varies in severity - night vision problems often begin in teens Vestibular Function (balance) Balance problems from birth Normal Normal to near-normal chance of later problems Hearing Cassin, B., & Rubin, M. L. (2006). U. Dictionary Of Eye Terminology 5th edition (5th ed., p. 271). Gainesville, FL: Triad Publishing Company (Fl). Guest, M. (n.d.). Usher's Syndrome & Retinitis Pigmentosa:Info. & Referrals. A-Z to Deafblindness. Retrieved July 1, 2010, from http://www.deafblind.com Nutting, P. (n.d.). Usher Syndrome Information on Healthline. Health Search Engine and Free Medical Information Healthline. Retrieved July 1, 2010, from http://healthline.com/galecontent/ushersyndrome-1 Usher's Syndrome. (n.d.). Wikipedia, the free encyclopedia. Retrieved June 29, 2010, from http://en.wikipedia.org Usher Syndrome. (n.d.). National Institute on Deafness and Other Communication Disorders [NIDCD]. Retrieved July 1, 2010, from http://www.nidcd.nih.gov/health/hearing /usher.html Created by: Connie Pester