About 3 out of 1000 newborns are affected by severe to profound hearing impairment at birth or in the first two years of life. Approximately 60% of these cases are due to genetic causes, of these 70% are non-syndromal, associated with an autosomal dominant (DFNA) (~ 20%), x-chromosomal / mitochondial associated (~ 1%) or autosomal recessive (DFNB) (~ 80%) inheritance follow. At present, 183 gene loci are known, of these so far 120 genes have been more exactly identified and characterized. These genes were classified based on the first descriptions in the literature, further or later findings were hardly considered.
The aim of this project is to systematically record the available results for these genes since the identification of the first gene GJB2 (Connexin 26) for hearing disorders in 1997.
For this purpose, a retrospective review of the literature is carried out with the help of systematic data acquisition, from a new perspective, of all genes and gene loci described for non-syndromic inherited hearing disorders. The additional parameters include questions on the onset, characteristics and course of hearing loss, other symptoms besides hearing loss, other diseases that are located on the same gene as hearing loss, but caused by a different mutation, and nationalities which the examined patients come from.
The results of the research data to date make it clear that some genes and their mutations are no longer correctly classified. With the help of a new and more precise classification, there are several starting points, on the one hand, one obtains a better overview of work that is still necessary, and on the other hand precise prognoses of a course of disease are possible.
