Birth deafness is linked to mutations in a gene, otoferlin. For gene therapy to be effective, it must be associated with another gene.
- In France, around 1,000 babies are born deaf each year.
- Gene therapy consists of modifying cells genetically, by introducing genetic material into them.
- In the context of congenital deafness, it could make it possible to compensate for the mutations of certain genes, essential for hearing
This is an important advance in research on congenital deafness. Researchers at the University of Oregon have recently made new discoveries, essential for the development of gene therapy. Their results were published in Molecular Biology of the Cell. This is “a new key piece of the puzzle” in research on gene therapy, they welcome.
A gene associated with congenital deafness
These researchers have been working for several years on a gene linked to congenital deafness: otoferlin. “For a long time, otoferline seems to have one trick up its sleeve“, compares Colin Johnson, one of the authors of the study. The scientists presumed that its only role was to encode the sounds in the hair cells, they are the ones who ensure the passage of information to the areas responsible for hearing. “Small mutations in otoferlin make people profoundly deaf“, recalls the researcher. But in this new work, he finds that he has another role: he participates in the development of sensory cells.
A new role for the otoferlin gene
During their work, Colin Johnson and his team used a truncated version of the gene, because it is too “heavy“for molecular therapy. However, this diminished version of the gene does not allow proper maturation of sensory cells.”This is surprising because otoferlin was known to help encode auditory informationemphasizes Colin Johnson, but it was not thought to be involved in the development of sensory cells.” For it to perform its role, the gene needs another gene, linked to the transmembrane domain. Without it, the sensory cells are slow to mature.
A test on zebrafish
In a test on zebrafish, scientists confirmed this hypothesis. They caused a mutation of the genetic heritage of these animals to truncate the transmembrane domain. They then noticed that this generated a drop in the production of otoferlin by the sensory cells, and a decrease in the activity of these cells in general. “The mutation also delayed the maturation of sensory cellsnotes one of the co-authors of the research Aayushi Manchanda, which surprised us. The results show that the transmembrane domain must be included in the design of any gene therapy.“We will still have to wait before this treatment is successful, and transforms the lives of patients with congenital deafness. In France, around a thousand babies are born deaf each year.
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