Hearing Loss Treatment 2015 News: Gene Therapy Allows Deaf Mice to Hear; Brings New Hope for Congenital Deafness

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A US research has successfully used gene therapy in correcting congenital deafness in mice. The new technique might be available for clinical trials in five to ten years according to the scientists.

The promising prospect for those who have inborn hearing loss comes in the form of a new gene therapy technique that tweaks genetic defects to reverse deafness.  The findings were published in the journal Science Translational Medicine and suggest that identifying and tweaking the gene that caused deafness could help restore auditory function.

Study authors Jeffrey Holt, Charles Askew and colleagues have identified TMC1 as the "deafness gene."

"Once we realized we had this deafness gene we began thinking about how we might be able to restore function in these patients with genetic hearing loss," Holt, who is also a researcher at Harvard and Boston Children's Hospital, said via NPR.

According to the scientists, deafness is primarily caused by genetic defects in the sensory hair cells of the inner ear. The hair cells that cannot regenerate accumulate and thus lead to hearing loss. However, hearing loss in adults and older people can be caused by noise-related or age-related factors.

For the study, the scientists replaced mutated TMC1 genes in the ear of their mice models to regenerate new cells. They deduced that the deaf mice can now hear some sounds because they jump when they hear loud sounds. Their auditory function was also confirmed through the mice's electrical brain signals.

"Our gene therapy protocol is not yet ready for clinical trials. We need to tweak it a bit more, but in the not-so-distant future we think it could be developed for therapeutic use in humans," Dr Holt said via The Independent.

The current technology for hearing loss and deafness are hearing aids and cochlear implants. According to NBC News, hearing aids assist by amplifying sounds in the wearer's ear, while cochlear implants substitute the damaged cochlea by providing sound signals to the brain to process hearing. However, these technologies do not have the same advantage as natural hearing.

Dr Margaret Kenna, a hearing loss specialist at the Boston Children's Hospital, praised the new study as it could help deaf children learn to speak easier.

"Current therapies for profound hearing loss like that caused by the recessive form of TMC1 are hearing aids, which often don't work very well, and cochlear implants," Dr Kenna said via Independent. "Cochlear implants are great, but your own hearing is better in terms of range of frequencies, nuance of hearing voices, music and background noises and figuring out which direction a sound is coming from," she said.