Summary: Researchers have identified ten novel genes and changes in the stria vascularis that appear to be associated with age-related hearing loss.
Source: King’s College London
Researchers led by King’s College London, Karolinska Institute and Erasmus University have identified 10 new genes linked with hearing loss and located the part of the ear affected.
The findings, published today in American Journal of Human Genetics, cast doubt on the understanding that age-related hearing impairment originates mainly from sensory hair cells. Researchers argue that the stria vascularis, a part of the cochlea in the ear, is a new target for treatments to help people with hearing loss.
Many people gradually lose some of their hearing ability as they get older, and an estimated 2.4 billion individuals will have some form of hearing loss by 2050. Age-related hearing impairment is a top contributor to years lived with disability and is also an important risk factor for dementia.
The team studied genetic analyses previously carried out in centres around the world using samples from 723,266 people from 17 studies who had clinically diagnosed or self-reported hearing impairment. This meta-analysis is one of the largest conducted in hearing genetics to date. The researchers identified 48 genes linked to hearing loss, including 10 new variants newly linked to hearing.
Further analysis looking at mouse genetics indicated that age-related hearing loss is due to changes in the stria vascularis which is necessary for hearing. The results provide targets for the basis of future research which could improve therapies against hearing loss.
Co-main author Frances Williams, Professor at King’s College London, said: “Our findings identify 10 genes newly linked with hearing loss. This study points to genes we could target for screening purposes, drug development and even gene therapy in the future. This study provides a solid foundation for ultimately improving therapies against hearing loss.”
Co-main author Christopher R. Cederroth, Associate Professor at the Karolinska Institute, said: “It was hypothesized since the 1970s that the stria vascularis may play a role in hearing loss in humans, but the molecular evidence for this was missing until today.”
About this genetics and hearing loss research news
Genome-wide association meta-analysis identifies 48 risk variants and highlights the role of the stria vascularis in hearing loss
Hearing loss is one of the top contributors to years lived with disability and is a risk factor for dementia. Molecular evidence on the cellular origins of hearing loss in humans is growing.
Here, we performed a genome-wide association meta-analysis of clinically diagnosed and self-reported hearing impairment on 723,266 individuals and identified 48 significant loci, 10 of which are novel.
A large proportion of associations comprised missense variants, half of which lie within known familial hearing loss loci.
We used single-cell RNA-sequencing data from mouse cochlea and brain and mapped common-variant genomic results to spindle, root, and basal cells from the stria vascularis, a structure in the cochlea necessary for normal hearing.
Our findings indicate the importance of the stria vascularis in the mechanism of hearing impairment, providing future paths for developing targets for therapeutic intervention in hearing loss.