The study was headed by researchers from the Danish iPSYCH research project, University of Aarhus and the Broad Institute, USA. The results have recently been published in the scientific journal Nature Genetics.
Autism is a neurological development disorder with highly variable features. Autism spectrum disorders are estimated to affect about one percent of the population. The researchers have tried to explain where the disorder stems from for decades. There have been many suggestions, but one factor has long been established – that genes play a very important role. However, only very rare genetic variants that carry a high risk for autism have previously been identified.
"When we look at autism, there is a heredity factor of up to eighty percent, so genes have a great deal of impact overall. Nevertheless, despite many years of work, identifying precisely which genes are involved has been very challenging", says Professor Mark Daly, one of the leading scientists of the study, who currently is the Director of the Institute for Molecular Medicine Finland FIMM at the University of Helsinki.
In this study, the researchers identified five common gene variants that increase the risk of autism. Furthermore, when combining the dataset with genetic data from related mental disorders, another seven gene variants were identified.
The research breakthrough was possible thanks to the large patient cohort and the possibility to combine data from several sources. The study was based on comparing the genome data of more than 20,000 autism patients with 170,000 individuals without autism.
The identified risk genes are important for the development of the brain and in particular the development of the cerebral cortex. These genetic findings provide an entirely new insight into the biological processes involved in the development of autism.
The researches also uncovered, for the first time, genetic differences between the different clinical subgroups of autism.
"This indicates that larger studies in the future will be able to pinpoint genes that separate the diagnostic groups and enable more precise diagnosis and advice for the individual person suffering from an autism disorder. We also hope that the genes we identify can provide an opportunity for developing actual treatment or prevention of the condition, which is something that we unfortunately cannot offer at present," said Professor Anders Børglum from Aarhus University, who is research head at iPSYCH and directed the study together with Dr. Daly.
Jakob Grove, Stephan Ripke, Thomas D. Als et al. Identification of common genetic risk variants for autism spectrum disorder. Nature Genetics online early, DOI: 10.1038/s41588-019-0344-8.
Director of the Institute for Molecular Medicine Finland FIMM
HiLIFE, University of Helsinki
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