A comprehensive whole-genome sequencing study of 170 individuals with autism spectrum disorder (ASD) is reported online this week in Nature Medicine. This study underscores the complex genetics of this disorder and provides a resource for ASD researchers to mine in the future to identify genetic risk variants.
Greater than 100 susceptibility genes have previously been associated with ASD suggesting the genetic causes of the disorder are diverse. Stephen Scherer and colleagues sequenced the genomes of 85 quartet families (families with two children who are both affected with ASD and their parents) to assess the degree with which affected siblings share common genetic alterations. The majority (69.4%) of affected siblings did not share common ASD-associated mutations. Those pairs of siblings that had shared mutations exhibited more similarities with respect to ASD symptoms than those pairs of siblings that harboured different mutations. In terms of genetic testing, these findings suggest that given the substantial genetic diversity between and within families, each ASD patient should be assessed individually to identify any genetic risk variants.