Study finds 44 genes linked to hearing loss

Researchers have identified 44 genes linked to age-related hearing loss which may help scientists better understand the genetic component of the condition, as well as identify potential targets for new treatment approaches.

‘Before our study, only five genes had been identified as predictors of age-related hearing loss, so our findings herald a nine-fold increase in independent genetic markers,’ said co-lead author Dr Sally Dawson of the Ear Institute at University College London (UCL).

In the study researchers at King’s College London and UCL asked over 250,000 volunteers between the ages of 40 and 69 to fill out questionnaires on whether they suffered from hearing difficulties or wore a hearing aid. The genetic data of participants was then analysed to identify the 44 genes.

‘We hope that our findings will help drive forward research into much-needed new therapies for the millions of people worldwide affected by hearing loss as they age,’ said Dr Dawson.

Using a genome-wide association approach, the genes were linked to the condition by looking at nine million genetic variants and seeing whether they differ in people with hearing loss compared to those without. Out of the 44 genes identified, 34 had not been previously linked to auditory impairment.

Dr Ralph Holme, executive director of Research at Action on Hearing Loss which funded the study, said: ‘These findings are incredibly significant. We believe they will speed up the discovery of treatments to slow or even halt the progressive loss of hearing as we get older, something which happens to at least 70 percent of over-70-year-olds.’

Although age-related hearing loss is the most common sensory impairment in the elderly, little is known about its cause, and only the use of hearing aids can help treat the condition. Loss of hearing can also lead to social isolation and disability and has been identified as a risk factor for dementia.

Armed with the new information provided by the study, researchers will now try to understand how each identified gene influences the auditory pathway, which in turn could help develop new treatments.

The study was published in The American Journal of Human Genetics.

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