Identifying Deafness Mutations

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Hearing loss is a commonly overlooked sensory disorder, even though it occurs all over the world. One type of deafness is autosomal recessive nonsyndromic deafness (ARNSD), a comparatively prevalent type of deafness in Iran. Working with researchers from Shiraz University of Medical Sciences, Emily Smith and Arya Mani from Yale University used DNA sequencing techniques to identify mutations that cause ARNSD. 

The research established that causative mutations were found in all ten Iranian families studied. Mutations were found primarily within GJB2 genes, which code for gap junction beta proteins. Novel mutations in the Iranian population were found also within the TMC1, ESRRB and MYO15A genes. These genes encode proteins involved in hearing. “These mutations often impair the function of cochlear hair cells,” Mani said. “For instance, TMC1[transmembrane channel like] is a pore-forming component of mechanosensory transduction channels in auditory and vestibular hair cells with important function in hearing.”

Identification of common mutations allows for early diagnosis of ARNSD. Earlier diagnosis, in turn, leads to proactive treatment plans, such as cochlear implants or speech therapy. “There are ongoing discussions in the media about people [who are] affected by deafness but are afraid of seeking help…[or] they try to deny their illness, so they are not as stigmatized. But once they are treated or wear their hearing aid, they catch up with challenges, and suddenly they see the world changes for them,” Mani said.


Dianatpour, M., Smith, E., Hashemi, S., Farazifard, M., Nezafat, N., Razban, V., & Mani, A. (2021). Identification of homozygous mutations for hearing loss. Gene,778, 145464. doi:10.1016/j.gene.2021.145464