Causes of usher syndrome - Essay Example

____________ ID: ________ ID: ________ Usher Syndrome Usher syndrome is an inherited disorder characterized by hearing and vision loss present at birth or shortly thereafter along with progressive vision loss caused by retina disorder called "retinitis pigmentosa" (RP). RP is a group of inherited diseases that cause night-blindness and peripheral (side) vision loss through the progressive degeneration of the retina, the light-sensitive tissue at the back of the eye that is crucial for vision". (2006a) Causes of Usher Syndrome "Usher syndrome is caused by a genetic mutation. It is passed from parent to child in a recessive manner. This means that a child inherits at least one defective gene from each parent in order to develop Usher syndrome. If a child inherits one defective gene, he or she will be a carrier and will not have any symptoms". (Rosenblum, Usher Syndrome) Types of Usher Syndrome Usher's Syndrome has four subtypes, however the fourth one is still under research and a little work is carried out in this respect: Type I: Usher syndrome type I is characterized by severe deafness which results in difficulties with balance due to inner ear problems, and progressive vision loss that begins in childhood. Subtypes: "Researchers have described seven distinct subtypes of Usher syndrome type I, designated as types IA through IG. Each of these subtype is caused by mutations in a different gene; however, the genes responsible for types IA and IE are still unknown. The subtypes are all considered part of Usher syndrome type I because affected individuals have similar signs and symptoms. Individuals with Usher syndrome type I are typically born completely deaf or lose most of their hearing within the first year. This type of Usher syndrome also includes problems with the inner ear that affect balance. As a result, children with such conditions begin sitting and walking later than usual. Balance improves with age as the children refine their leg muscle control. Vision loss caused by PR becomes apparent in childhood and causes light-sensing cells in the retina to gradually deteriorate. The deterioration begins with night vision loss, followed by blind spots that develop in the side (peripheral) vision. These spots enlarge and merge into a doughnut shape, producing tunnel vision". (2006b) Type II: Usher syndrome type II is characterized by milder hearing loss present from birth and progressive vision loss that begins in adolescence or adulthood. Subtypes: There are three subtypes of Usher syndrome type II, designated as types IIA, IIB, and IIC. "The hearing loss associated with Usher syndrome type II mainly affects high tones and ranges from mild to severe. Affected children have problems like hearing high, soft speech sounds, such as those of the letters d and t. The degree of hearing loss varies within and among families with this condition. People with type II Usher syndrome do not have difficulties with balance caused by inner ear problems (which is a symptom of other forms of Usher syndrome). Vision loss begins during the teenage years or in adulthood. The progression of vision loss can be unpredictable, but Usher syndrome type II usually does not lead to complete blindness". (2006b) Type III: Usher syndrome type III is still under controversial research, which begins, in the early decades of life. "Unlike the other forms of Usher syndrome, infants with Usher syndrome type III are usually born with normal hearing. Hearing loss typically begins during the first two decades of life, after the development of speech, and progresses over time. By middle age, most affected individuals are profoundly deaf. People with Usher syndrome type III may also develop difficulties with balance due to inner ear problems. These problems vary among affected individuals, however vision loss begins in late childhood or adolescence and its progression is unpredictable". (2006b) Diagnosis: Usher syndrome is usually diagnosed by conducting the following tests: Visual function tests: Electroretinography A retinal examination Hearing tests Balance tests for all patients age ten years and older: Electronystagmography (ENG) Research and Treatment: Currently there is no cure for Usher syndrome. Nearly all the developed nations are eager to find the actual genetic cause and the treatment of this disease. However "intensive research is currently under way to discover the cause, prevention, and treatment of the vision loss with Usher syndrome. While not a cure, a specified dose of vitamin A has been found to slow the progression of RP in some individuals with typical RP and Usher syndrome type II. Research to precisely identify the specific genes involved in each Usher syndrome type is moving at a rapid pace. In the near future it would be possible to perform a test on genetic material from blood and other cells to determine if the specific gene defect causing Usher syndrome is present. When available, this testing will provide an accurate genetic diagnosis useful for early detection of the disorder, and for defining the risks of other family members or future offspring being affected". (Research1) "Scientists with the National Institute on Deafness and Other Communication Disorders (NIDCD) have identified protocadherin-15 as a likely player in the moment-of-truth reaction in which sound is converted into electrical signals. (Protocadherin-15 is a protein made by a gene that causes one form of type 1 Usher syndrome, the most common cause of deaf-blindness in humans.). By this, they discover the actual mechanism how a human hear, i.e. how mechanical signals are converted into electrical signals for the brain to identify sounds. Depending on this work, researchers might be able to answer the actual cause of hearing disorder in usher syndrome". (Research2) "Currently, 12 loci have been found to cause Usher syndrome. A locusis a small segment of chromosome on which one or more genes are housed. For seven of the 12 loci, genes and the proteins that they encode have been identified. The genes that cause Usher syndrome are MY07A, USH1C, CDH23, PCDH15, and SANS, which cause USH1; USH2A, which causes USH2; and USH3A, which causes USH3. The resulting proteins that the genes encode help cells in the retina, the part of the eye that receives images of objects, and the cochlea to function". (Research3) "In April 2003, NIDCD researchers, along with their research collaborators pinpointed a mutation, named R245X, of the PCDH15 gene that accounts for a large percentage of USH1 cases in today's Jewish population. Because of this finding, researchers conclude that Jewish infants with bilateral, profound hearing loss who lack another known mutation that causes hearing loss should be screened for the R245X mutation. If a child's USH1 is discovered early on, before she loses the ability to see, then that child is more likely to benefit from the full spectrum of intervention strategies that are available to help her communicate and participate in life's activities". (Research3) Possible treatments for Usher syndrome can be categorized by the two sensory organs that are affected: The Ear Cochlear Implant Technology Benefits People with Hearing Loss "One of the outstanding recent scientific accomplishments that has benefited people affected by hearing loss is the cochlear implant. The cochlear implant is a small electronic device that is surgically implanted in the mastoid bone behind the ear and in the inner ear. The surgeon places the device through an incision that is masked by the ear". (Research4) A cochlear implant consists of four parts: 1. Microphone that picks up sounds from the environment 2. Speech processor that chooses and organizes sounds from the microphone 3. Transmitter and receiver stimulator that translates the sounds into electrical impulses 4. Series of up to 22 electrodes that transmit the electrical impulses to the auditory nerve "The majority of totally deaf patients who receive cochlear implants are able to detect medium to loud sounds, including speech at comfortable listening levels. For many patients, cochlear implants assist in communication by improving their ability to lip-read. In a smaller number of patients, the implant facilitates an understanding of words or sentences without the use of lip-reading.Results vary depending on factors such as age at time of deafness, age at implant surgery, duration of deafness, condition of the remaining auditory nerve fibers, and training". (Research4) The Eye "Scientists have been very encouraged by the results of a six-year clinical study reported in June 1993 concerning vitamin A palmitate and RP. Researchers wanted to determine if increasing the amount of vitamin A palmitate in the diet could slow the progression of retinal degenerations. A carefully designed study showed that taking vitamin A palmitate could slow the progression of retinal degeneration for some people who have RP or Usher syndrome type II. Subjects in the study included people with several common forms of RP and Usher syndrome type II. Patients with Usher syndrome type I were not studied. Therefore, recommendations cannot be made for those who have Usher syndrome type I. Patients with a daily consumption of about 18,000 International Units (IU) of vitamin A were found to have a lower rate of retinal degeneration, as measured by ERG, than patients not taking these doses of vitamin A. Taking vitamin A palmitate did not completely stop retinal degeneration, but the researchers found a 20 percent slower average annual decline of remaining retinal function in people taking the supplement. They concluded that the slowing could mean additional years of useful vision for many people with RP. For example, a person starting the daily supplement at age 32 could expect to retain some useful vision until the age of 70, while a person not taking the supplement would lose useful vision by age 63". (Research4) "The same study that found these encouraging results from taking vitamin A palmitate supplements also looked at the effect of vitamin E supplements on retinal degeneration. In the case of vitamin E, the opposite effect was found. People taking 400 IU daily of vitamin E were found to have a faster rate of retinal degeneration than those in the other groups. This led to the recommendation that people with RP should avoid high-dose vitamin E supplements. However, there is no evidence that normal dietary or small supplemental amounts of vitamin E have an adverse effect on the progression of RP". (Research4) Herbal Treatment "Herbal treatment is designed by Chinese researchers in order to improve symptoms and slow disease progression, correct imbalance and adjust immune system, prevent and treat complications, improve the prognosis, and most importantly, to restore function, boost energy and strong body for better health and quality of life. The purpose of herbal treatment is not to take the place of necessary medical treatment but to fasten the recovery process. Combination of the both is a better choice". (Treatment) "During observations on 22 patients receiving treatment with this herbal combination, 4 cases were judged as healing (full recovery and symptom free), 17 cases other significant improvement. Physicians judged the clinical efficacy to be good or excellent in 95.5%. (Treatment) Since there is no prevention and 100% cure from this disorder, it is better to start educating the children with specific programs and services, this not only helps reduce the communication and learning problems that can result from hearing and vision loss but is also beneficial to them in making their professional career. Children education with Usher syndrome in Canada In Canada children suffering from Usher syndrome usually start learning to cope through work with their mentors, however according to Canadian Research such children or people require assistive devices according to the level of Usher syndrome in order to assist them in their daily as well as professional lives. The devices, which assist them, include: Telatouch Telebraille Computer with screen reader or large print software such as zoom text Computer with Braille display Braille, large print, larger font on computer screen Magnification equipment such as monocular or magnifier Magnifying glasses CCTV (Closed Caption Television) Video Camera with LCD Display Telephone with volume control Hearing aid with built in FM system Smoke detector and fire alarm with flashing light Alert Master (the individual wears a pager that produces different vibrations for different sounds in the home) Vibrating alarm for bed Special measuring device for liquids White cane Braille or talking watch. (2006d) Meeting for parents of children who were deaf-blind were held in Calgary, Alberta, Toronto and Ontario according to which it was found that most of the parents were facing difficulty in finding quality interveners for their children. In Canada, Usher syndrome is treated at educational level under the strict guidance of experienced and trained mentors, who are responsible for: Team building, listening and supporting as a member of the school based team. Professional growth for classroom teachers, support staff and parents. Promoting students towards personal independence. Building individual educational plans for children suffering from usher syndrome with school team. Use of Braille and mobility instruction. Computer technical support. Recommendations for such students. Vision screening and assessment. Observing and analysis of each individual according to liaison with Special Education Technology Canada. The class teacher considers and advice on the best lighting and contrasting conditions for the particular student and depending upon the "blind" skills the level of Braille is suggested. In those conditions where the student has sufficient vision to enable learning, the use of Braille is lowered down. As far as educational and professional opportunities are concerned, such students are given equal benefits and support to lead a normal life. A realistic career guidance follows them as they are not completely deaf and blind, their professional life must be transparent for the employer or placement jobs. There is still a need of well-trained Intervenors, public Intervention programs and providing community awareness and education about combined visual and hearing impairment. Unfortunately not much work is done in this aspect. There is a need for improved physical accessibility, which features people suffering from Usher syndrome. "Changes should include: improved lighting, accessible signs on doors, stairs, elevators, escalators, etc. Service providers housed in public facilities should provide information about their offerings in large print, Braille and computer disk". (CNSDB) If public education activities were increased, this would alleviate frustrations experienced by those citizens who are one way or the other suffering from Usher Syndrome. In this way they would lead and prepare their children towards a better future. Future of Usher Adults in Canada The Canadian Government particularly with respect to 'Usher syndrome', suggests that such individuals who missed out on obtaining education due to this disorder, must obtain at least secondary education or skills in order to benefit significantly from job related training or particular education. For such 'high potential return' individuals, a policy is designed to provide them with a substantial payoff (depending upon the extent of disability). "Canadian jurisdictions have used some of the available policy levers for encouraging few employers to train their employees. While a few provinces provide training grants, Quebec is the only province with a train-or pay scheme. The federal government has provided substantial financial support for the development of a sectoral approach to defining and dealing with skill requirements. Although there is evidence of significant training-related activity through the sector councils, there is none in terms of their effectiveness in improving access to learning opportunities for the disabled". (ServiceCanada) Some Canadian firms have launched initiatives to provide training to such disabled workers with impressive results. But these firms remain in minority. However, the Government of Canada is funding seven projects through the Youth Employment Strategy, which offers three programs for disabled: Skills Link, Summer Work Experience and Career Focus. These programs provide flexibility to choose from a range of activities that can be tailored to meet individual needs. "The Skills Link program helps youth facing barriers to employment to acquire the skills, knowledge and work experience they need to participate in the job market. The Career Focus program provides financial support to Canadian employers and organizations to provide post-secondary graduates with career-related work experience in Canada and abroad. This helps the graduates particularly disabled to acquire advanced employment skills and improve their chances of developing careers in their fields". (ServiceCanada) Work Cited 2006a, accessed on July 10, 2006 from 2006b, accessed on July 10, 2006 from 2006c, accessed on July 10, 2006 from htp://www.wrongdiagnosis.com/u/usher_syndrome/intro.htm> 2006d, accessed on July 10, 2006 from Canadian, Spring 2006 Vol. 13: 3, from CNSDB NIDCD, accessed on July 10, 2006 from < http://www.nidcd.nih.gov/health/hearing/usher_new.asp> Research1, accessed on July 10, 2006 from http://www.blindness.org/usher-syndrome.asp Research2, accessed on July 10, 2006 from Research3, accessed on July 10, 2006 from Research4, accessed on July 10, 2006 from Rosenblum Laurie, Usher Syndrome, accessed on July 10, 2006 from ServiceCanada, accessed on July 2006 from Treatment, accessed on July 10, 2006 from Read More