The parents of a U.K. toddler say it's "absolutely mind-blowing" to see their daughter, enrolled in a gene therapy trial, hear for the first time.

A deaf child has received a new gene therapy treatment with “mind-blowing” results that have allowed her to hear for the first time. Opal Sandy, from Oxfordshire, UK, is the first British patient and youngest child in the world to receive this groundbreaking treatment, according to a press release from Cambridge University Hospitals.

Hearing loss affects about 1.5 billion people, while congenital deafness—hearing loss present at birth—affects approximately 1.7 out of every 1,000 children born in the U.S. The OTOF-related deafness experienced by Opal is exceedingly rare, affecting just 200,000 people worldwide.

A deaf toddler can now hear normally in one ear after being treated with a pioneering experimental gene therapy in a clinical trial.

After receiving treatment to correct a faulty gene, 18-month-old Opal Sandy can now hear.

Opal Sandy, an 18-month-old from England, is the youngest child to come close to “normal hearing levels” in a gene therapy trial to aid her genetic deafness.

Dr. Richard Brown reveals the pioneering science that just changed the life of a UK toddler. Deaf baby can now hear after breakthrough gene therapy Watch: Mitch McConnell blasts Tucker Carlson over Uk

A deaf toddler is now able to hear after becoming the first patient in the world to receive a new gene therapy.

Opal Sandy, who was born deaf because of a rare genetic condition, and can now hear unaided for the first time after receiving ground-breaking gene therapy at 11-months-old, at he

Opal Sandy can hear almost perfectly after groundbreaking surgery that took just 16 minutes