Gene therapy trial gives deaf children hearing in both ears

Sub: Science and tech

Sec: Biotechnology

Context:

Five children who were born deaf now have hearing in both ears after taking part in an “astounding” gene therapy trial that raises hopes for further treatments.

More about the therapy:

The children were unable to hear because of inherited genetic mutations that disrupt the body’s ability to make a protein needed to ensure auditory signals pass seamlessly from the ear to the brain.
Within weeks of receiving the therapy, the children had gained hearing, could locate the sources of sounds, and recognised speech in noisy environments.
The US-Chinese team reported improvements after treating the deaf children in one ear, but the intention was always to give hearing in both ears.
If they can hear in both ears, the children can work out where sounds are coming from, a capability important for everyday situations such as talking in groups and being aware of traffic when crossing the road.

Procedure of the gene therapy:

The gene therapy is injected during a minimally invasive surgical procedure, so treating both ears doubles the time that patients spend in surgery.
Treating both ears also raises the risk of a stronger immune reaction, triggered when the body’s defenses react to the virus that delivers the therapy.

What is Gene Therapy?

Gene therapy aims to fix a faulty gene or replace it with a healthy gene to try to cure disease or make the body better able to fight disease.
It holds promise as a treatment for a wide range of diseases, such as cancer, cystic fibrosis, heart disease, diabetes, hemophilia and AIDS.
Gene therapies are of two types, germ-line gene therapy (GGT) and somatic cell gene therapy (SCGT). In GGT, germ cells are modified by introduction of correct/functional genes into their genome. It is heritable and is passed onto the next generation.