Genetic patches developed for hereditary deafness

Researchers at Radboudumc have developed a method that can be used to combat a hereditary form of deafness that often develops at a later age. They have shown that the method works in cells. The results have been published in the scientific journal Molecular Therapy – Nucleic Acids, as was announced today on the International Day of Hearing.

The Radboudumc research can offer a solution for people with DFNA9 in the somewhat longer term. This is an abnormality in which people who are a little older suffer from hearing loss. It often occurs from the age of 40, 50 and is because someone has received a mutated version of the DFNA9 gene from one of the parents.

Mutated proteins

People hear worse because mutated proteins are formed by the genetic abnormality. They attack good, non-mutated proteins in the hearing cells. The mutated proteins are still cleared away at a young age, but as a person gets older, this is less successful.

“There is a tipping point. Waste accumulates, the hearing cells function worse and die over time,” says Erik de Vrieze, who conducted the research together with Erwin van Wijk. “After years of hearing well, DFNA9 patients suddenly notice that their hearing deteriorates, sometimes very quickly. Until at some point they become deaf.”

An estimated 1500 people in the Netherlands and Belgium have this hereditary form of deafness.

‘Essential link’

The researchers at Radboudumc have developed what they call “a genetic patch”. In doing so, use is made of rna, which, as a ‘messenger’, translates between the genetic properties that are stored in a person’s DNA and the body proteins that also contain those properties.

“The unique DNA error in the DFNA9 gene is reflected in the rna translation,” says De Vrieze. “We have made a piece of RNA that fits exactly there. And that also immediately signals that the entire messenger RNA must be cleaned up. In this way an essential link is lost and the wrong protein is not or hardly produced anymore. “

Testing on mice

The researchers have shown that the method works at the cellular level, the so-called proof of concept. They are now continuing to test on mice. If it turns out that it also works there, the genetic patch can also become available to humans. That is a long-term process. Researcher Erwin van Wijk expects that this will take another 5 to 10 years.

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