Gene treatment: hope at last for deaf children

The treatment of congenital deafness, which affects up to three out of every thousand newborn babies, finally looks set to benefit from a breakthrough.

Up until now, cochlear implants have been the main solution for these children, but the procedure is invasive and doesn't restore the full richness of natural sounds. Targeted gene therapy now offers a promising alternative, capable of restoring hearing in children suffering from deafness linked to the OTOF gene.

How does gene therapy work?

Unlike other forms of genetic deafness, the mutation of the OTOF gene does not alter the structures of the inner ear, but it does prevent the production of an essential protein: otoferlin. To correct this defect, researchers inject a modified virus carrying a healthy version of the gene directly into the auditory cells. This “molecular courier” then enables the auditory neurons to transmit sound correctly to the brain again.

A recent ground-breaking clinical trial has produced spectacular results. The study involved ten participants aged between one and twenty-four, all suffering from this rare form of deafness. The injections took place in five hospitals, with rigorous monitoring combining blood tests and ear examinations.

The results can be seen as early as the first month:

• 62% improvement in objective brainstem tests
• 78% improvement in behavioural assessments

Two patients regained near-normal hearing, one of whom heard his first sounds three days after the injection.

The most impressive progress was made by children aged between 5 and 8, while the efficacy appeared to be slightly lower in younger children and young adults.

After a year's follow-up, no serious side-effects were observed. Only a few participants experienced a slight drop in white blood cells, without any major consequences. This success marks a real breakthrough in the treatment of genetic deafness, as gene therapy finally offers curative - and no longer merely compensatory - treatment for hereditary deafness.

Other teams are already working to target the more common genes involved in hearing loss, bringing renewed hope to a whole generation of children who have hitherto been cut off from the world of sound.

(MH with LpR - Source : actusanté.net - Picture : Unsplash)