Deaf boy can now hear after breakthrough gene treatment
A recent breakthrough in gene therapy has enabled an 11-year-old boy, Aissam Dam, who was born profoundly deaf due to a rare genetic abnormality, to gain the ability to hear. This significant medical advancement was carried out at the Children’s Hospital of Philadelphia (CHOP) and represents a first in the United States. The gene therapy aimed to correct an abnormality in a very rare gene responsible for the production of otoferlin, a protein essential for the inner ear’s hair cells to convert sound vibrations into chemical signals to the brain. In Aissam’s case, a harmless virus modified to carry working copies of the otoferlin gene was injected into the cochlea. This procedure resulted in the hair cells beginning to produce the missing protein, enabling them to function correctly. Almost four months after the treatment in one ear, Aissam’s hearing improved to a level of only mild-to-moderate hearing loss [❞].
In a separate but related development, a novel gene therapy approach developed by a team co-led by Zheng-Yi Chen of the Massachusetts Eye and Ear Infirmary and Harvard Medical School, in collaboration with Fudan University in China, has enabled five children born deaf to hear. The children, aged between 1 and 7, had an inherited mutation of the OTOF gene, which is crucial for transmitting signals from the ear to the brain. This therapy involved overcoming a significant technical challenge due to the size of the OTOF gene, which was too large for the viral vector commonly used in gene therapies. The researchers successfully split the gene into two parts, delivering both halves into the cochlea, where cellular machinery then assembled the complete protein. This restoration of protein function led to the ability of the inner ear cells to transmit signals to the brain. The five children who responded to the treatment showed significant improvements in hearing and speech perception, with some even able to recognize speech in noisy environments and have telephone conversations [❞].
These breakthroughs represent significant advancements in gene therapy for hearing loss, providing hope for future treatments for various genetic forms of deafness.
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