When we report on genetic research related to autism, it can be easy to get overwhelmed quickly. After all, there are thousands of potential genes that could be associated or have something to do with autism at some level. More so, it seems that every few weeks there’s a new study reporting on new genes, genetic mutations, or genetic relationships that shed fresh light on autism.
However, in groundbreaking news, the largest genetic study of autism spectrum disorder, first authored by Stephen Sanders, PhD, of the University of California, San Francisco, has identified 65 genes that contribute to autism, including 28 of which there is “very high confidence” that they play a role in the risk of developing ASD.
Furthermore, the study confirms that there are also six larger areas of the genome that are prone to de novo copy number variants (dnCNVs), which contribute to autism risk.
According to Dr. Sanders, “Autism is largely a genetic disorder, so it follows that finding the genes involved in autism is a logical first step to understanding the biology of autism. The discovery of 65 autism risk genes and six risk regions serves as a foundation for understanding the neurobiology of autism. By considering when, where, and how these genes interact, we can focus on the developmental time period, brain region, and cell type that is disrupted in autism,” he said.
One area that Sanders and his team are focusing in on is the disparity in the diagnosis of autism between genders, with males being diagnosed at a rate of four to one female. However, while both genders are at equal genetic risk for autism, girls with ASD have a much larger number of dnCNVs, which suggests that girls are protected against ASD, unless their genetic mutation reaches a tipping point.
“We see a higher burden of autism risk factors in affected females compared to affected males, suggesting that more risk is required for an autism diagnosis in females than males, as would be expected if females were protected,” Dr. Sanders further explained. “Second, we find that the mutations are distributed randomly across the genes between males and females, suggesting that autism risk factors are the same in both sexes, rather than there being a set of male-only risk genes,” he added.
Sanders went on to conclude that these findings will provide him and other researchers with an increased understanding of autism, enabling them to develop therapeutics. By discovering these mutations—which are present in 10% of children in autism—the scientists should gain greater insight into a child’s future development, though more work is required to elucidate long-term outcomes.