A groundbreaking gene therapy trial at Cambridge University has allowed one of the youngest children in the world to hear for the first time in her life. Opal Sandy, an 18-month-old toddler born with total deafness due to a fault in the OTOF gene, was given a working copy of the gene through a surgical procedure. The results have been described by Opal's family as "mind-blowing."

The OTOF gene is responsible for producing a protein called Otoferlin, which facilitates communication between the cochlea, the inner ear, and the brain. In a 16-minute procedure carried out just before Opal's first birthday, she received an infusion of the working copy of the OTOF gene in her right ear. Within a few weeks, Opal could hear loud sounds, much to the amazement of her parents.

Opal's mother, Jo Sandy, described the moment she saw her daughter respond to sound as "absolutely mind-blowing." Initially, she thought it might have been a fluke, but further testing and observations confirmed the significant improvement in Opal's hearing abilities. The toddler's response to sound was so remarkable that her cochlear implant, which directly stimulates auditory nerves, was removed.

As the weeks went by, Opal's hearing continued to improve. At the 24-week mark after the surgery, she could even hear whispers. Doctors described her level of hearing in her right ear as "near normal." Along with the ability to hear, Opal has also started speaking words like "Mama" and "Dada."

Professor Manohar Bance, the chief investigator of the trial at Cambridge University Hospitals Foundation Trust, expressed his excitement at the results. He described the outcomes as "perfect" and "better" than expected, marking a new era in the treatment for deafness. He believes that this gene therapy approach is just the beginning and holds immense potential.

The gene therapy procedure and treatments have been well-tolerated by Opal, with no reported adverse effects. The trial, known as the Chord trial and conducted by Regeneron, an American company, is being carried out in multiple locations in the U.S., Britain, and Spain. In the first phase of the trial, low doses of gene therapy are administered to three deaf children in one ear, including Opal. If the safety is confirmed, more children will receive infusions in both ears in subsequent phases.

This remarkable development in gene therapy for congenital deafness offers hope for the estimated 1.7 in every 1,000 children born in the U.S. affected by this condition. While devices like hearing aids and cochlear implants provide assistance, they do not fully restore natural hearing. The success of Opal's treatment and other data from the Chord trial were presented at the American Society of Gene and Cell Therapy annual conference in Baltimore.

Opal's story highlights the life-changing potential of gene therapy and signals a promising future for the treatment of deafness. With continued research and advancements in this field, more children like Opal may have the opportunity to experience the joy of hearing for the first time.