At least 14 to 15 percent of children with autism will have some form of these identified gene mutations, said Geshwind.
But the findings won't necessarily tell parents much. While having the mutation may increase the risk of autism, it doesn't necessarily mean the child will develop the disorder. The findings also can't tell researchers how severe a child's autism will be.
"We are far from the point where there's predictive information," said Daly.
"This shows that we are making a lot of progress in identifying the causes of autism," said Geshwind, who believes more genes associated with autism, and what they mean, are yet to be discovered.
"Genetics is here," said Geshwind, "and it's going to be clinically relevant very soon."