A reanalysis of data from more than 2 million children in Sweden suggests inherited genetic factors account for 83 percent of autism risk1.
A 2014 study using the same dataset pointed to an equal contribution from genetics and the environment, but experts in the field were critical of the findings, citing flaws in the study’s methods.
Then, to their surprise, the researchers came up with a heritability estimate of 85 percent using an overlapping dataset of nearly 800,000 Swedish children2. That result prompted them to revisit their earlier work.
In both studies, non-inherited genetic factors called de novo mutations are included in the 17 percent of autism risk dubbed ‘environmental.’ De novo mutations are thought to be important in autism.
