baby's ear
(Photo : Pexels / Burst)

Opal Sandy, an eighteen-month-old baby, was born with complete hearing loss because of a congenital defect. Now, thanks to a groundbreaking therapy, she was able to hear unaided after receiving just one dose.

Deaf Baby Girl Hears Unaided Thanks To Gene Therapy

Opal's condition is known as auditory neuropathy, which is a genetic defect that is rare and due to nerve impulse disruptions from the inner ear up until the brain. Such a condition is associated with the OTOF gene's mutation. This impairs otoferlin protein production, which is vital for the communication between inner ear sensory cells and the auditory nerve. Without this protein, the pulses get translated to electric signals, but do not reach the brain.

Children with an OTOF gene mutation typically pass screenings for newborns, which implies that such a type of hearing loss is usually undetected until later on.

Around 1.5 billion individuals are affected with hearing loss, while roughly 1.7 of every 1,000 children born in the US are affected with congenital deafness. In Opal's case, her condition is extremely rare, as it is known to just affect 200,000 people all over the world.

Opal was the first UK patient, and the youngest one in the world, to receive the gene therapy injection that is meant to repair the defect that is responsible for her deafness. Within three weeks of her injection, she started responding to sounds. After almost six months, she was observed to have functional hearing in her right ear, which is treated. She also no longer needs to have a cochlear implant for her left ear.

She is now able to recognize the voices of her parents and respond to certain words, such as "bye-bye" and "Dada." During times when her mother wants a kiss, Opal moves her head and presents her rosy cheek.

Jo Sandy, the mother of Opal, explains that when Opal was able to unaided hear them clapping, it was quite mind-blowing. They were extremely happy when the clinical team granted confirmation at 24 weeks that the baby was also picking up softer speech and sounds. Opal's hearing was described to be near normal, which thrilled everyone with the great results.

ALSO READ: Two Gene Therapies Could Restore Hearing Among Children With Hereditary Ear Condition, Clinical Trial Results Reveal

Revolutionary Gene Therapy

This clinical trial, dubbed CHORD, was sponsored by Regeneron, an American biotech firm, and started a year ago. It targets the determination of whether cutting-edge gene therapies could aid in hearing restoration among children who have the condition that also affected Opal.

The outcomes of the trial have been quite extraordinary. According to professor Manohar Bance, the trial's leader and an ear surgeon from Cambridge University Hospitals NHS Foundation Trust, explains that the results are incredible and go beyond his expectations.

Such a type of gene therapy has been anticipated for a long while to be possible game-changers for individuals who struggle with hearing defects.

The CHORD trial currently enrolls children and infants across Spain, the UK, and the US. It assesses the gene therapy's efficacy and safety.

The exact gene therapy, called DB-OTO, involves a single injection to the inner ear that provides a correct copy of the gene that is defective. In the case of Opal, she had an infusion that contained a harmless virus that carried an OTOF gene functional copy. This was delivered through inner ear injection during surgery with general anesthesia.

Such a method shows potential in becoming an alternative to traditional cochlear implants and hearing aids. Though these devices aid with sound amplifications, they do not address the genetic issues that underlie the matter.

Martin McLean, the National Deaf Children's Society's Senior Policy Advisor, explains that several families will be welcoming such developments. They may also look forward to knowing more about the outcomes in the long run for children who receive such treatment.

The 24-week results of Opal, along with other data pertaining to the CHORD trial, are being shown at the ASGC (American Society of Gene and Cell Therapy) in Baltimore this week.

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