USHER SYNDROME -
Symptoms and Cause
This genetic condition causes hearing loss from birth and progressive loss of sight due to retinitis pigmentosa (RP), which causes degeneration of the retina. Often the first symptom of RP is night blindness, followed by narrowing side vision leading to what is called "tunnel vision".
Two types of Usher syndrome
In Usher Syndrome Type 1, there is severe damage to the cochlea from a very early age and therefore the child has severe deafness from birth. The child usually develops problems with night vision and tunnel vision due to RP in the first 10 years of life.
People with this condition usually communicate by signing. This clearly can become more difficult as vision deteriorates.
In Usher Syndrome Type 2, the hearing loss is more variable, ranging from mild to severe. Symptoms of RP usually develop from late adolescence to late twenties. Communication is enhanced in these people with hearing aids and lip reading.
It is important to consider Usher syndrome in any child who is having considerable hearing problems, since this may be evident before the symptoms of RP develop. A common early symptom may be the delayed development of speech. Early diagnosis in children is important so that a child's educational needs can be met, and career choices made.
Figures from the USA and Scandinavia suggest that 3 to 6% of all people born deaf have this condition. In Victoria, a recent survey of people with RP showed that 8% have Usher syndrome.
Diagnosis will normally include the following:
- Assessment by an ear, nose and throat specialist to ensure correct diagnosis of the hearing loss.
- Assessment by an ophthalmologist to assess the presence and severity of RP.
- Special hearing and vision tests (such as ERG) to confirm the diagnosis. (An Electro retinogram (ERG) measures the electrical activity in the retina. A person with RP has a significantly abnormal ERG).
This disease is a genetic autosomal recessive disorder.
Click here for Inheritance Patterns
Living with Usher syndrome
Loss of both sight and hearing affects communication, mobility and daily living. It can make independent living more difficult to achieve.
We depend on sight and sound to communicate. People with Usher syndrome depend more on their sight for communication, lip-reading and reading sign language. The effects of vision loss can cause serious problems in communication, particularly in poor light.
Members of both the vision impaired and hearing impaired communities need to be aware of this condition to provide support to those members of their communities who have this condition.
Special consideration and understanding is important because both senses of vision and hearing are affected to a greater or lesser degree. Advice about mobility and supporting aids may need to the modified to ensure maximum benefit.
These issues also need to be considered by medical and other people who provide advice and care for people with Usher syndrome.
With the appropriate support, training and aids, people with Usher syndrome can live independently. Services for a person with Usher syndrome will depend on age and severity of the hearing and vision problems, but will normally include the following types:
- Genetic counselling
- Audiological support, including fitting of hearing aids when necessary.
- Educational training that, at different ages, may include:
- preschool and school assessment and placement,
- independent living training, and/or
- career guidance.
- Rehabilitation counselling that may include:
- family support,
- orientation and mobility training, and/or
- communication aids.
The state branches of the Deaf-Blind Society and Deaf and Blind Children's Institute should also be contacted.