Hakonarson, Schellenberg and Wong presented the findings Tuesday during a London-based teleconference. They are published online today in Nature.
"This is the first crack in the facade of this disease," according to Schellenberg. He said the findings represent "the next step in understanding the fundamental molecular biology of what's happening in autism."
"And this really gets us a major jump, we think, in terms of knowing what targets to look at," he said, referring to the development of therapies to combat both the risk for and onset of autism.
For the first study, the researchers conducted a genetic analysis of more than 10,000 children, of whom 4,500 had a diagnosis of autism spectrum disorder, a grouping of neural developmental problems involving verbal skills as well as social interaction and behavior.
The effort yielded two autism-associated culprits -- variants of the CDH10 and CDH9 genes -- which the researchers suggested could underlie the risk for autism in about 15 percent of cases.
For the second study, researchers looked specifically at the genetic "roadmap" of children with autism spectrum disorder and isolated two genes along the so-called "ubiquitin pathway" -- the UBE3A and PARK2 genes-- that appeared vulnerable to deletion/replication variations. The variations seemed to undermine the genes' ability to ensure smooth cell communication across brain synapses. That study involved 859 children with an autism spectrum disorder and more than 1,400 children without such disorders.
Collectively, these findings emphasize the complexity of the genetic underpinnings of autism, the researchers said. And they stressed that having these genetic predispositions does not necessarily mean a higher risk for the disorder in the absence of other critical factors.
"We think that, in most cas
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