Gene therapy found to restore hearing in mice with genetic deafness

SAN FRANCISCO–Injection of a gene into the inner ear of mice born with genetic hearing loss was found to restore the laboratory animals’ hearing within two weeks of the treatment, according to a preclinical research study published in the July 26 issue of the journal Neuron. The experiment was conducted by Lawrence Lustig, PhD, and colleagues at the University of California, San Francisco.

The research team used as subjects mice with hereditary deafness caused by a mutation in a gene coding for a protein called vesicular glutamate transporter-3 (VGLUT3). This protein is crucial in enabling inner hair cells to send the signals that make hearing possible.

According to the study, all of the mice that were injected had improved hearing. Among those that were treated as adults, the improvement lasted between 7 weeks and 18 months, while the improvement lasted for at least 9 months in mice that received the treatment as newborns. The method used to deliver the VGLUT3 gene caused no damage to the inner ear of the animals.

Lustig, the senior author of the study, stated, “This is the first time that an inherited, genetic hearing loss has been successfully treated in laboratory mice, and as such represents an important milestone for treating genetic deafness in humans.”

Because the treatment was found to be both safe and effective in the lab animals, the findings hold promise for future applications in human. Lustig said, “For years, scientists have been hinting at the possibility of gene therapy as a potential cure for deafness. In this study, we now provide a very real and big step towards that goal.”