UK toddler, born completely deaf, hears for first time after pioneering gene therapy

A UK toddler's hearing was restored after undergoing the world's first-ever pioneering gene therapy trial. The child was born completely deaf, and the doctors said this development marks a new era in treating deafness.

According to reports by The Guardian, the toddler named Opal Sandy, from Oxfordshire, was born completely deaf due to auditory neuropathy, a rare genetic condition that disrupts nerve impulses travelling from the inner ear to the brain due to a gene defect. Sandy's parents were shocked to know that their daughter could hear for the first time after the treatment.

Jo Sandy, Opal's mother, said, "I couldn't really believe it. It was … bonkers."

The rare genetic condition auditory neuropathy can be caused by a fault in the OTOF gene, which makes a protein called otoferlin. This protein enables cells in the ear to communicate with the hearing nerve. A functional gene copy is infused into the ear to treat this hearing defect through this groundbreaking gene therapy.

The report suggested that the 18-month-old toddler received an infusion containing a functional copy of the defective gene during a breakthrough surgery that lasted just 16 minutes. The surgery took place at Addenbrooke's Hospital, a part of the Cambridge University Hospital's NHS Foundation Trust that has been running the CHORD trial.

The CHORD Gene Therapy Clinical Trial initiated by the University of Cambridge uses gene therapy to restore hearing in children. The gene therapy- DB-OTO is meant for children with OTOF mutations. A modified adeno-associated virus (AAV1) is used to carry the working gene into the patient for treatment.

Professor Manohar Bance, an ear surgeon at the trust and chief investigator for the trial, stated that the initial results were "better than I hoped or expected" and could cure patients with this type of deafness.

He added, "There's been so much work, decades of work, to see something that actually worked in humans finally." He also stated that Sandy is the first and youngest patient to receive the therapy.

According to the outlet, another child received the gene therapy treatment at the university and showed positive results. The Chord trial has three parts with three deaf children, including Sandy, who only received a low dose of gene therapy in one ear.

As per the outlet, a different group of three children will be infused with a high dose on one side of the ear as a part of the trial. If the results are safe, more children will receive a dose in both ears. In total, 18 children will be recruited to the trial worldwide.

Professor Manohar stated, "The trial is just the beginning of gene therapies."