News of World Medicine

Geneticists have found out how to restore the hearing to deaf people

A revolutionary gene therapy was able to restore the hearing to deaf mice. The animals began to hear even a quiet whisper (sounds in the range of up to 25 dB), BBC reports. According to scientists, a similar approach may cure deaf people. The therapy corrects errors which were caused by the defects of auditory hairs.

For this purpose a synthetic virus was used. It acted as the delivery method of gene therapy. The results were impressive. According to Dr. Jeffrey Holt from Boston Children Hospital, such effective restoration of hearing has not yet been able to achieve.

According to statistics, about 50% of all kinds of deafness are associated with DNA errors. For example, the experimental mice had Usher syndrome (The genome of "Instructions" for the auditory hairs construction in the inner ear is disturbed). This leads to disruption of auditory hairs organization. In its turn, the synthetic virus infected the right "instructions" for the auditory hairs construction.

It is known about 100 different types of genetic defects leading to hearing loss. Consequently, every hearing impaired person will need his own unique gene therapy. Also, the scientists are still not sure whether the virus-deliver is 100% safe for using in humans. The current version of the synthetic virus was created on the basis of adenovirus.

As for the durability of effect, for today it is known that the therapy works for at least six months. The last question is a time window. For example, the therapy succeeded, when the mice were administered with the virus at the birth. But the results were negative, when the virus was administered in 10 days after birth.

Source: BBC