Search results
Results from the WOW.Com Content Network
Defects in this gene lead to the most common form of congenital deafness in developed countries, called DFNB1 (also known as connexin 26 deafness or GJB2-related deafness). [7] One fairly common mutation is the deletion of one guanine from a string of six, resulting in a frameshift and termination of the protein at amino acid number 13. Having ...
Many genes related to deafness are involved in the development and function of the inner ear. Gene mutations interfere with critical steps in processing sound, resulting in hearing loss. Different mutations in the same gene can cause different types of hearing loss, and some genes are associated with both syndromic and nonsyndromic deafness.
Other causes of congenital hearing loss that are not hereditary in nature include prenatal infections, illnesses, toxins consumed by the mother during pregnancy or other conditions occurring at the time of birth or shortly thereafter. These conditions typically cause sensorineural hearing loss ranging from mild to profound in degree. [3]
All three subtypes are caused by mutations in genes involved in the function of the inner ear and retina. These mutations are inherited in an autosomal recessive pattern. The occurrence of Usher syndrome varies across the world and across the different syndrome types, with rates as high as 1 in 12,500 in Germany [2] to as low as 1 in 28,000 in ...
Mutations in a single copy of SNAI2 have also been found to cause patches of hair depigmentation without any other symptoms. [25] Type 2E is caused by an autosomal dominant mutation in the gene SOX10. [4] Rarely, a mutation in a gene other than those currently known may be responsible for a Waardenburg syndrome with features of type 2.
Mitochondrial mutations causing deafness are rare: MT-TL1 mutations cause MIDD (Maternally inherited deafness and diabetes) and other conditions which may include deafness as part of the picture. TMPRSS3 gene was identified by its association with both congenital and childhood onset autosomal recessive deafness.
Deafness is defined as a degree of loss such that a person is unable to understand speech, even in the presence of amplification. [15] In profound deafness, even the highest intensity sounds produced by an audiometer (an instrument used to measure hearing by producing pure tone sounds through a range of frequencies) may not be detected. In ...
These are diseases that have deafness as one of the symptoms or as a common feature associated with it. Many of the genetic mutations giving rise to syndromic deafness have been identified. In nonsyndromic cases, where deafness is the only finding, it is more difficult to identify the genetic mutation although some have been discovered.