Hearing loss in mice with a form of progressive deafness has been slowed by a one-off treatment using the CRISPR genome editing method. This advance may lead to a treatment that aids to prevent hearing loss with certain inherited deafness.
Our body contains almost two copies of every gene, but in some situations a mutation in one of these copies can often lead to disease. Theoretically, disorders such as these could be treated by switching off the mutated copy and leaving the healthy copy. Researchers are now trying this using CRISPR.
A sensory biologist at Oregon health and Science University, Peter Barr-Gillespie states, “ It’s a pretty significant piece of work, it shows that CRISPR- mediated gene editing can lead to real amelioration of hearing loss in vivo”
The mouse model has the same point mutation in the mouse version of Tmc1 that in the human gene leads to gradual hearing loss, commonly around childhood. The mice begin to loose some of there hearing at around three weeks, and are completely deaf by eight weeks due to the death of the hair cells.
David Liu a Harvard chemical biologist and his colleagues designed a guide RNA that targets the disease-causing duplicate of the gene, which is autosomal-dominant, to allow the health allele to function.
This type of deafness caused by the dominant mutation of Tmc1 is extremely rare- only a few families are known to suffer with it. Although, this same approach may work for other dominant forms of inherited deafness.
Journal Reference: Nature, DOI: 10.1038/nature25164 : https://www.nature.com/articles/nature25164