Advanced gene therapy may reverse hearing loss caused by genetics: study – Fox News

Researchers at Boston Children’s Hospital found that replacing a mutated protein in the inner ear reversed severe hearing loss in mice, according to a study published in the journal Science Advances. The first-of-its-kind gene therapy technique involved replacing a mutated protein called stereocilin, (STRC), in the inner ear. The investigators said it reversed severe hearing loss in mice and in some cases, restored it to normal levels of hearing, according to a news release.

Closeup of examining ear with an otoscope

The researchers explained in the release, that hearing loss has been associated with mutations of at least 100 different genes. The researchers stated that up to 16 percent of genetic hearing loss could be linked to the gene STRC, which they noted is also the second most common genetic cause.

“Patients who carry STRC mutations lack cochlear amplification entirely and, as a result, suffer from reduced auditory sensitivity and have difficulty with frequency discrimination and speech perception”, the authors stated in the published report in the peer-reviewed journal.

In order to hear sound, sensory hair cells in the inner ear need to make contact with the tectorial membrane the researchers reported. The membrane responds to sound by vibrating and converting the vibrations into signals that travel to the brain.

The investigators say the stereocilin protein acts like a scaffold and helps the hair cells stand up in an organized bundle, which allows the hair cell tips to touch the tectorial membrane.

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“If stereocilin is mutated, you don’t have that contact, so the hair cells are not stimulated properly,” Jeffrey Holt, Ph.D., a scientist in the Department of Otolaryngology and Neurology at Boston Children’s, said.

“But importantly, the hair cells still remain functional, so they are receptive to the gene therapy. We think this will provide a broad window of opportunity for treatment – from babies to adults with hearing loss,” Holt, who is also the study’s senior investigator, said in the release.

Tinnitus is not a condition itself, but rather is a sign of one, such as age-related hearing loss, an earwax blockage, or stiffening of the bones of the middle year, according to the Mayo Clinic.
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Using a generated mouse model, the researchers designed a dual-vector protein-recombination strategy to replace full-length wild-type Strc in the outer hair cells of mice that carry STRC mutations, according to the study. The investigators discovered what they described as “robust restoration of full–length stereocilin protein” in the mice and noted hair bundles that had a normal appearance and were able to contact the tectorial membrane, according to …….

Source: https://www.foxnews.com/health/genetic-cause-hearing-loss-reversed-gene-therapy