The American Foundation Fighting Blindness has awarded a grant of 2.4 million euros to a collaboration between the Radboud University Medical Center and the English University College London. The researchers will investigate how often the hereditary eye disease RP17 occurs worldwide, so that more people can be diagnosed. They will also study disease mechanisms and possible treatment options.
Thousands of people in the Netherlands have a hereditary disease of the retina. An error in their DNA causes the disorder. They suffer from reduced vision or even blindness. In forty percent of the cases the genetic cause is still unknown. This is because some rare errors in the DNA are difficult to detect, or because our understanding of what causes these inherited eye diseases is still limited.
In 2020, after a 35-year search, a group of researchers from the Radboudumc and others found an important cause of such a hereditary eye disease. Group leader Susanne Roosing of the Department of Human Genetics explains: 'We discovered the genetic cause of the condition retinitis pigmentosa type 17, or RP17, in the DNA of a large Dutch family with this condition. We have now found 300 people with this genetic cause in 22 families worldwide.'
The Foundation Fighting Blindness is now investing 2.4 million euros in follow-up research. 'Thanks to this money we can further investigate how often RP17 occurs worldwide,' explains researcher Suzanne de Bruijn. ‘We are also developing a guideline for diagnostic centers. The changes in the DNA that we have found are very complex, and it is still difficult to understand why one change in this area of DNA does lead to RP17, while another change in the same piece of DNA does not cause any problems. We will further investigate these genetic changes. In this way, people will get a correct diagnosis and hopefully also a treatment in the future.'
Exactly how the genetic cause leads to disease is not yet clear. 'We see that several relatively large errors in the same region in the DNA cause the chromosome to fold up incorrectly', explains Roosing. 'We think that this causes the cells in the retina to produce a certain protein (GDPD1) that does not belong in the eye. This protein probably causes the problems due to damage to the light sensitive cells in the eye. We are going to find out whether this is indeed the case.'
The researchers will also use the grant to develop a genetic therapy against this hereditary eye disorder. De Bruijn: 'We think that different errors in the DNA found in individual families are all responsible for the production of the same protein. If this protein is indeed the culprit in RP17, then we want to try whether we can block the production of this protein using smart genetic methods.'
The American foundation is giving the 2.4 million euro grant to a collaboration between the Radboudumc and UCL in London. The project will run for five years.