Opal Sandy was born with a mutation in the Otof gene, which causes inherited deafness. However, she became the first patient to receive a revolutionary gene therapy treatment before turning a year old. Today, at 18 months old, Opal can hear sounds as quiet as a whisper and is even beginning to speak, having already said the words ‘mummy’ and ‘daddy’.

Opal Sandy's journey was part of a groundbreaking clinical trial that spanned across the UK, Spain, and the US. Under the care of a dedicated team of scientists at Addenbrooke's Hospital, University of Cambridge, England, Opal's progress was closely monitored.

Opal has a mutation in the Otof gene that results in the production of non-functional hair cells in the cochlea. Hair cells are responsible for detecting sound from the environment. To treat this, a gene therapy that involves delivering a functional copy of the Otof gene into the damaged cells using a harmless virus was used. The drug, developed by Regeneron, was administered through an infusion into the right ear under general anaesthesia.

A few weeks later, Opal began to hear loud sounds, like clapping, in her right ear. After six months, her doctors at Addenbrooke's Hospital in Cambridge confirmed that her ear had almost normal hearing for soft sounds, including very quiet whispers, BBC reports.

An electric cochlear implant was also placed in her left ear. This device replaces the non-functioning hair cells by picking up the vibrations of sound waves and directly stimulating the auditory nerve. The nerve then transmits the "sound" to the brain. The patient's sister, Nora, who also has the same type of deafness, uses an electric cochlear implant and is doing well.

The girls' parents, Jo and James Sandy from Oxfordshire were astonished by the results of Opal's gene therapy. However, they emphasised that the decision to allow their child to participate in testing this treatment was not an easy one.

"We were quite nervous to go down a different path to one that we knew had already worked so well for our eldest daughter. But it also sounded like a really unique opportunity," Opal's mother admitted in an interview with BBC.

Source: BBC, The Guardian