Usher Syndrome is always inherited in a recessive pattern. So far, researchers have found 11 genes that are associated with the three main subtypes of the syndrome. Usher Syndrome is a genetic disease that occurs when there are mutations (defects) in genes that are important for the function of both photoreceptors in the retina and hair cells in the cochlea, or inner ear. The prevalence of Usher Syndrome varies from country to country, but it is a rare condition affecting approximately one in 10,000 people. What is the cause of Usher Syndrome and how is it inherited? Usher type 3 is a very rare form of Usher and is generally found in people with their family origins in Finland. In type 2 Usher Syndrome the features of RP usually become obvious during their teenage years. Patients with Usher type 2 also have an early onset hearing loss but the deafness is less severe than in type 1 and thus the child will benefit from hearing aids and will develop intelligible speech. The deafness is generally so e arly in onset and so severe that hearing aids may not be of value (although cochlear implants may be beneficial), and patients fail to develop intelligible speech. People with Usher type 1 develop profound deafness from birth and early childhood symptoms of RP. different clinical types of Usher Syndrome: type 1, type In Australia, types 1 and 2 are the most common types. Deafness is the first symptom to become apparent, usually from birth. The major symptoms of Usher Syndrome are hearing loss and an eye disorder called Retinitis Pigmentosa, or RP. Some people with Usher Syndrome may also have problems with their balance. Usher Syndrome is responsible for the majority of cases of deafblindness, but the rate of progression of vision loss can vary widely from person to person and even within members of the same family. Usher Syndrome causes a gradual decline in vision because two types of photoreceptor cells, known as the rod and cone cells, begin to degenerate and die. The vision loss aspect of the syndrome is due to a form of Retinitis Pigmentosa which affects th e photoreceptor cells, which are responsible for capturing images from the visual field. While patients with Retinitis Pigmentosa do have a greater tendency to develop hearing difficulties as they age compared to the general population, the term Usher Syndrome is reserved for patients where the hearing loss becomes obvious at a very early age. Usher Syndrome refers to a group of genetic conditions that have both hearing loss and progressive deterioration in vision due to Retinitis Pigmentosa (RP).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |