Scientists report they have found 52 genes that are critical for hearing. The work was published yesterday in Nature Communications from the Medical Research Council (MRC) Harwell, which led the analysis by the International Mouse Phenotyping Consortium.
In this study, the team tested 3,006 different strains of knock-out mice for signs of hearing loss. To do this, the mice were assessed with rising volumes of sound at five different frequencies. They were considered hearing impaired if they could not hear the quieter sounds for two or more frequencies.
From these studies, the team found 67 genes that were associated with hearing loss and reported that 52 of them had not been previously linked with hearing loss. The identified genes varied in how they affected hearing. Some of them were identified as mild to severe hearing loss or actually impaired the mouse from hearing at different frequencies.
The knock-out mice tested so far in this study represented only about 15 percent of mouse genes, so the researchers estimate that if the entire genome is searched there will be at least 450 genes required for hearing function.
"Our findings identify 52 genes that have previously not been recognized as being critical for hearing. These increase our knowledge of the many genes and molecular mechanisms required for hearing and also provide a shortlist of new genes to investigate to discover the genetic basis of many human hearing loss syndromes. Testing these genes in people with hearing loss may help to improve diagnosis and counseling of patients," said senior author Steve Brown, Ph.D., Director of MRC Harwell.
The next steps for the group are to determine the role that each of the proteins encoded by these genes has within the auditory system. With these studies, the researchers might be able to find targets for human hearing loss syndromes.
Image: Ear human internal anatomy. Image courtesy of Patrick J. Lynch, medical illustrator [CC BY 2.5], via Wikimedia Commons.