Members Login
Search
Wednesday, Dec 03, 2008 | 01:57 PM
Madisons Foundation - Moms And Dads In Search Of Needed Support
Usher Syndrome
Sunday, 15 August 2004
Last Updated Sunday, 15 August 2004
What
The Usher Syndromes are genetic disorders that cause blindness, deafness, and lack of balance control. The Usher Syndromes are divided into three types (I, II, and III) based on severity of symptoms and age of onset.Who
Usher Syndrome affects 1/16,000 to 1/50,000 people. About 50% of people with both hearing and vision loss have Usher Syndrome. In this population, about 33-44% have Usher Syndrome Type I and 56-67% have Usher Syndrome Type II. The frequency of Usher Syndrome Type III is unknown, but it is especially prevalent in the Finnish population.Signs and Symptoms
The Usher Syndromes are characterized by hearing impairment that affects both ears and retinitis pigmentosa which causes a gradual loss of vision that begins as a loss of night vision with narrowing of the visual field (tunnel vision). Each type has a different age of symptom onset and degree of visual and hearing impairment. Cataracts, or clouding of the lens of the eyes, may also develop. Usher Syndrome Type I: • Retinal degeneration or vision loss beginning in childhood • Severe to profound hearing impairment beginning at birth • Vestibular dysfunction (lack of balance control) Usher Syndrome Type II: • Retinal degeneration or vision loss during adolescence or adulthood • Moderate to severe hearing impairment beginning at birth • Normal vestibular function Usher Syndrome Type III: • Variable age of onset for vision loss • Progressive hearing loss • May have vestibular dysfunctionPossible Causes
A variety of different genes can cause Usher syndrome. Currently, there are seven known gene mutations that will cause Usher Syndrome Type I, three known gene mutations that will cause Usher Syndrome Type II, and two known gene mutations that will cause Usher Syndrome Type III. Each of these syndromes are inherited in an autosomal recessive pattern. This means that the child receives one altered copy of the gene from each parent. For the children of parents who are carriers of the altered gene, 1/4 will have Usher Syndrome, though the severity can vary.Diagnosis
Diagnosis of Usher Syndrome is based on clinical evaluation of vision and hearing loss, degree of balance control, and family history of the disorder, if one is present. People with Usher Syndrome have normal health and intellectual development. Because children with Usher Syndrome Type I have a great degree of hearing loss, early intervention is needed to protect their language development. Additionally, they may not begin to walk until the age of 18 months to 2 years because of the lack of balance control. Children with Usher Syndrome Type II will begin walking at a normal age because they do not have any problems with their balance. Children with Usher Syndrome Type III may or may not have problems with their balance. They will begin speaking at a normal age because they do not lose their hearing until adolescence or adulthood. Prenatal genetic testing is available only when another family member is affected with the syndrome.Treatment
Children diagnosed with Usher Syndrome Type I do not benefit from hearing aids due to the severity of hearing loss. Cochlear implantation, in which an electronic device is surgically placed into the ear to stimulate neurons that are involved in hearing, should be considered in these cases. Children with Usher Syndrome Type II will benefit from hearing aids, but a few may need cochlear implantation. There are currently no medications that will completely stop the progression of vision loss. However, studies have shown that vitamin A might help slow the progression in Usher Syndrome Type II; its effectiveness has not been studied in Usher Syndrome Type I. Vitamin A supplementation must be carefully monitored by a physician because excessive amounts of vitamin A has harmful side effects. All patients and their families should work with professionals who have experience in teaching individuals who are hearing and visually impaired how to communicate and develop daily life skills.Prognosis
The progression of vision loss is variable. Although peripheral vision is slowly lost over time, central vision may remain acute. Patients should see an ophthalmologist regularly to assess their vision and to prevent other complications, such as cataracts. Since children with Usher Syndrome Types I and III have balance control problems, they should undergo training that will help them become more aware of their bodies and how they are positioned in the environment. This should help them with maintaining balance while performing daily activities. Children with Usher Syndrome will have to undergo a great amount of therapy and education to help them learn how to communicate and perform daily functions.Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.Weblinks
American Association of the Deaf-Blind:
This association was developed by people who are deaf-blind. Their mission is to provide education, networking opportunities, and support for its members.
Foundation Fighting Blindness:
This foundation provides funding for research in diseases that cause blindness.
National Family Association for Deaf-Blind:
This is a non-profit organization that provides support for individuals who are deaf-blind and their families.
Self Help for Hard of Hearing People:
Provides information for people who have hearing impairments. This is an advocacy group that raises public awareness and provides support and education.
The National Information Clearinghouse on Children who are Deaf-Blind
This is a federally-funded service that provides information and referrals.