Next-generation DNA sequencing technologies are enabling the identification of deafness-causing genetic variants.
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At least half of all cases of deafness that develop from birth through infancy in developed countries have a genetic basis, as do many cases of later onset progressive hearing loss. To date, at least 1,000 mutations occurring in 64 genes in the human genome have been linked to hearing loss.

In “Next-Generation Sequencing in Genetic Hearing Loss,” published in Genetic Testing and Molecular Biomarkers, Denise Yan and Xue Zhong Liu, Mustafa Tekin, and Susan Blanton review the advances in high-throughput, massively parallel DNA sequencing that amplify and repeatedly sequence only specific regions of the human genome in which genes linked to deafness are likely to be found.

This strategy, known as “targeted resequencing,” allows researchers to find disease-related gene mutations much more quickly than searching through the entire genome. To date, at least 1,000 DNA variants at more than 130 sites in the human genome have been identified that can cause hearing loss not associated with other symptoms or syndromes.

“Over the next decade, most of the variant genes responsible for deafness will be identified and such knowledge will lead to the development of practical treatments,” conclude the authors.