Five children born completely deaf can now hear in both ears thanks to amazing advances in science and medicine, after taking part in a groundbreaking Chinese-American gene therapy trial that raises hopes for further treatments. After treatment, child patients were able to localize sound sources in space, recognize human speech, and also dance to music. Theguardian.com reports that there is currently no pharmacological treatment available for congenital deafness.
The children in question were deaf at birth due to inherited genetic mutations, which interfere with the body's ability to produce proteins needed to ensure the smooth passage of auditory signals from the ear to the brain.
Doctors and experts from Fudan University in Shanghai treated the hearing of children of various ages, from one to eleven years old. The goal of the treatment was for the children to gain sufficient spatial hearing and be able to recognize which direction sounds were coming from.
Stunning results
Within a few weeks of completing the therapy, the children actually regained sufficient hearing, they were able to locate sources of sounds in space and recognize speech in noisy environments. Two children were even recorded dancing to music, a team of scientists reported in the journal Nature Medicine.
Dr. Zheng-Yi Chen, a scientist at the Massachusetts Eye and Ear Clinic, part of Harvard Medical School in Boston, said: The results are stunning, he added, and researchers continue to see dramatic progress in children's hearing abilities.
The therapy uses an inactive virus to “sneak” functional copies of a gene called OTOF into the inner ear—specifically, adeno-associated virus (AAV) serotype 1 carrying the human OTOF transgene, or AAV1-hOTOF. This gene is damaged and nonfunctional in children.
Once viruses with the right "template" gene are injected, cells in the ear use this new genetic material as a template to churn out functional copies of a key protein important for hearing, called otoferrin.
Each of the children showed improvement
Scientists showed a video a two-year-old boy who responded to his name three weeks after treatment and even danced to music after 13 weeks, while before the therapeutic injections, he showed no reaction to any of the stimuli.
Another patient, A three-year-old girl initially did not respond to sounds, but 13 weeks after treatment she was able to understand sentences and form some words on her own. The oldest patient was an 11-year-old girl who initially showed no response to tones played at different pitches before therapy, but six weeks later responded to all of them. She was also able to participate in speech training from the 13th week.
More than 430 million people worldwide suffer from disabling hearing loss, of whom about 26 million have been deaf since birth or shortly after. Up to 60 percent of childhood deafness is caused by genetic factors. The children included in the study suffered from DFNB9, a disease caused by mutations in the OTOF gene, which cause roughly 2-8 percent of all congenital or so-called prelingual (occurring before speech development) hearing loss.
The goal of the treatment was for the children to gain sufficient spatial hearing and be able to recognize which direction sounds were coming from. Source: unsplash.comResearch advances
In January this year, the same American-Chinese team reported positive developments after a similar treatment of deaf children, but in this case it was only in one ear. However Scientists have always intended for children to be able to hear in both ears. As long as both ears are functioning properly, children can tell where sounds are coming from, which is important in everyday situations. such as conversations within groups of people or auditory orientation in traffic when crossing a road, the researchers said.
However, many more and larger studies will be needed to assess the benefits and risks of the aforementioned therapy in more detail. Gene therapy is administered via injections during a minimally invasive surgical procedure, while treating both ears doubles the time patients spend in surgery.
However, injecting treatment into both ears also increases the risk of a stronger immune response, which can be triggered when the body's defense system reacts to the virus that is mediating the treatment. However No serious adverse effects were noted during the study.
"We hope to expand this study and that this approach can also be applied to deafness caused by other genes, or even non-genetic causes. Our ultimate goal is to help people regain their hearing, regardless of how the loss was caused," stated Dr. Chen.
A new era in deafness treatment
Last month, in addition, A British toddler has become the first person to have hearing fully restored in one ear after similar gene therapy targeting hearing loss caused by mutations in the OTOF gene. The surgical procedure lasted 16 minutes.
Professor Manohar Bance, the lead researcher of this British study, said at the time that the therapy in question marks a new era in the treatment of deafness.