The International Mouse Phenotyping Consortium (IMPC) including the German Mouse Clinic, Helmholtz Zentrum München, succeeded in shedding light on more than 50 new hearing genes. The study was recently published in Nature Communications.
The developmental and physiological complexity of the auditory system is likely reflected in its underlying gene set. Over 100 deafness genes had been identified in mouse and human but the full extent of the genetic landscape involved in auditory dysfunction remains unknown.
Within the framework of the IMPC all relevant organ systems of over 3000 knock-out mice were analyzed so far. In order to identify genes required for hearing function, the involved centers applied the auditory brainstem response (ABR) test, that assesses hearing at five frequencies – 6kHz, 12kHz, 18kHz, 24kHz and 30kHz – as well as a broadband click stimulus. The scientists identified 67 genes associated with hearing loss, of which 52 had not been previously linked with hearing loss before. The knock-out mice tested so far represented only about 15% 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.
The study provides a shortlist of new genes to investigate the genetic basis of many human hearing loss syndromes, and further exploring these genes will increase our knowledge of the molecular mechanisms required for hearing. Testing orthologues of these new candidate genes in people with hearing loss may help to improve diagnosis and counselling of patients.
A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction. Bowl MR et al., 2017. Nat Commun. 2017 Oct 12;8(1):886. doi:10.1038/s41467-017-00595-4.