New study into Stargardt disease looks into the genetic chances of a child's risk of developing low vision

A new study published by researchers from the Radboudumc in the American Journal of Human Genetics counts the chance of passing on Stargardt disease when someone with Stargardt disease and someone without it have a child together. Using these results, doctors can more accurately inform people with Stargardt disease about their child’s risk of developing low vision.

“Imagine that you slowly start to see worse and worse,” outlines PhD student Stéphanie Cornelis. “You get the news that this is not going to get better and your vision will continue to deteriorate. The doctor tells you that the form of visual impairment you have, the rare Stargardt disease, is genetic. Therefore, there is a chance that your children will also have this condition. Then an important question is, how likely is it that if you have children, they will also have this disease?” Until now, there was no good answer to this. The new study by the group of Professor Frans Cremers of the Department of Human Genetics at the Radboudumc in Nijmegen is changing that.

Stargardt disease occurs in one in ten thousand people and is a so-called recessive disease. This means that this type of low vision only develops if the child has inherited an ABCA4 gene with an error from both parents. The researchers from the Radboudumc previously published an overview of all the errors in DNA that can cause Stargardt disease but now they went further and calculated the risk that offspring will get the disorder.

Their new study is based on data from almost 6000 people with this disease and a control database of the general population. Despite that the risk assessment is complex because not all combinations of errors in the ABCA4 gene lead to disease, it appears that when someone with Stargardt disease and someone without it have a child together, the risk can be counted to be between 0.7% and 3.1% that the child will also develop Stargardt disease.

According to Cremers, the complex calculation of the chance of disease used in this study can also be applied to other recessive diseases: “I think that in the future we can also use this method for risk estimation very well for example in Usher syndrome, in which both hearing and vision are affected, or in cystic fibrosis. These diseases also can be due to severe and mild mutations.” …. “In addition, the other parent (the one without the condition) can be genetically tested,” Cremers explains. “One can then determine the likelihood of disease even more precisely. But genetic screening is expensive and not available everywhere in the world.”

Publication: This research was published in American Journal of Human Genetics: Personalized Genetic Counseling for Stargardt Disease: Offspring Risk Estimates Based on Variant Severity. Stéphanie S. Cornelis, Esmee H. Runhart, Miriam Bauwens, Zelia Corradi, Elfride de Baere, Susanne Roosing, Lonneke Haer-Wigman, Claire-Marie Dhaenens, Anneke T. Vulto-van Silfhout, Frans P.M. Cremers.

For more information on the publication: https://www.radboudumc.nl/en/news-items/2022/risk-of-eye-disease-calculated-for-child-of-parent-with-stargardt-disease

This work was funded through Fighting Blindness.

Contact: frans.cremers@radboudumc.nl or (mobile) +31-6-23738881.