A revolutionary technique has allowed six deaf youngsters, aged one to eleven, to hear for the first time. Children born with a gene mutation that prevents the development of a critical hearing protein took part in experimental groups in China and the United States.
According to the Daily Mail, scientists delivered a gene called otoferlin (OTOF) into the inner ear, causing cells to create the missing protein. After 26 weeks of treatment, children’s hearing levels improved to up to 70% normal.
Significant progress was shown as early as six weeks into the treatment. A one-year-old responds to his name for the first time, and another child articulates words like father, mother, grandma, sister, and “I love you,” which she couldn’t do before.
Aissam Dam, 11, heard for the first time this week at Children’s Hospital of Philadelphia (CHOP) following therapy, a first in the United States.
Zheng-Yi Chen, DPhil, a Harvard Medical School professor and study author for China’s experiments, suggests that untreated hearing impairment in children can result in improper brain development.
Gene therapy, which has already been approved for illnesses such as sickle cell disease and severe hemophilia, is now being tested for genetic deafness.Globally, approximately 34 million children suffer from deafness or hearing loss, with genes responsible for up to 60% of instances.
Dam, who was born “profoundly deaf,” and five Chinese infants share a highly rare anomaly in their OTOF gene, resulting in a faulty gene that inhibits otoferlin production. Otoferlin is a critical protein for the “hair cells” of the inner ear, which transform sound vibrations into chemical impulses conveyed to the brain.
Defects in the Otoferlin gene are infrequent, accounting for one to eight percent of hearing loss cases at birth.
Dam underwent surgery in October to treat his deafness. The technique entailed partially raising his eardrum and introducing a harmless virus designed to contain functional copies of the otoferlin gene into the fluid inside his cochlea.
As a result, the hair cells in his inner ear resumed manufacturing the previously missing protein, allowing them to function normally.
Dam’s hearing in one ear has recovered dramatically after nearly four months of treatment, with just mild-to-moderate hearing loss remaining. Dam, according to the Children’s Hospital of Philadelphia (CHOP), is now “literally hearing sound for the first time in his life.”
Dr. John A. Germiller of CHOP stated that gene therapy for hearing loss, a goal pursued for more than two decades, is now a reality. The successful correction of a rare gene defect in Dam’s instance may open the way for future applications targeting the over 150 other genes that cause juvenile hearing loss.