A revolutionary gene-therapy technique has enabled a deaf child to hear unaided.

A revolutionary gene-therapy technique has enabled a deaf child to hear unaided. 

A revolutionary gene-therapy technique has enabled a deaf child to hear unaided

Opal Sandy received treatment shortly before her first birthday, and six months later, she can hear noises as delicate as a whisper and is beginning to speak, saying words such as "Mama," "Dada," and "uh-oh." 

The medication, administered as an infusion into the ear, replaces the defective DNA that causes her form of genetic deafness. 

Opal is participating in a trial that is recruiting patients from the United Kingdom, the United States, and Spain. 

Doctors in other nations, notably China, are looking into similar treatments for Opal's Otof gene mutation.

Her parents say the results have been mind-blowing, but allowing Opal to be the first to test this Regeneron medication was exceedingly challenging. 

"It was really scary, but I think we'd been given this unique opportunity," 

Her five-year-old sister, Nora, suffers from the same type of deafness but manages well with an electrical cochlear implant. 

Rather than making sound louder, as a hearing aid does, it provides the "sensation" of hearing by directly stimulating the auditory nerve, which interacts with the brain, bypassing the damaged sound-sensing hair cells in the cochlea.

In contrast, the therapy employs a modified, harmless virus to introduce a functional copy of the Otof gene into these cells. 

Opal received therapy in her right ear while under general anaesthesia, and a cochlear implant was placed in her left ear. 

Just a few weeks later, she noticed loud sounds, such as clapping, in her right ear. 

After six months, her specialists at Addenbrooke's Hospital in Cambridge confirmed that her ear had practically normal hearing for delicate sounds, including very quiet whispers.

More than half of all children's hearing loss is inherited. 

Prof Bance expects that the trial will lead to the use of gene therapy to treat other frequent types of hearing loss. 

Hearing loss caused by a mutation in the Otof gene is rarely diagnosed until children are two or three years old, when speech delays are expected.

However, genetic testing for at-risk families is available through the NHS. 

Opal's experience, along with other scientific data from the experiment, will be discussed at the American Society of Gene and Cell Therapy meeting in Baltimore, USA. 

Martin McLean of the National Deaf Children's Society stated that more options were appreciated. 

"With the correct support from the beginning, deafness should never be a barrier to happiness or fulfillment," he stated.