Common genetic variants - the differences found among multiple families - are responsible for the majority of genetic risk for autistic disorder, according to a study published online this week in Nature Genetics. The results will help with future studies on the genetic basis of autism spectrum disorder (ASD).
Recent studies on the genetic architecture of ASD have disagreed about whether genetic variants specific to families, known as “rare variation”, or more commonly shared genetic variants in a population, are more likely to correlate with ASD.
Joseph Buxbaum and colleagues looked into this issue by looking at blood samples from Swedish individuals between the ages of 10 and 65 who were diagnosed with ASD. This is a unique population as Swedish government has detailed medical and birth records for its citizens. By studying the genetic differences between Swedes with and without autism, the researchers were able to calculate the risk of developing autism given the patient’s DNA sequence. They found that contrary to some reports, genetic variants that are shared between families, rather than those specific to a single family, were responsible for most of the risk of developing autism.