These findings could help parents who may be considering another child understand their overall quantifiable risk of autism recurrence. But these findings do not mean that every family is at the higher spectrum of risk, Ozonoff said.
Ozonoff said the findings could also change the way pediatricians examine infants with familial risk for autism.
"These children need careful monitoring and special surveillance [more] than what would be done at a well child visit," said Ozonoff.
A closer look at infants at higher risk could lead to earlier detection of autism symptoms, Ozonoff said.
"The whole point of early detection is to get the children referred and into intensive intervention as soon as possible," said Ozonoff. "The more effective intervention the earlier, the better they'll do."
Hawn said he credits Aaron's early detection and subsequent intervention for allowing him to progress further than Logan, who was not even monitored for autism at Aaron's age.
"The whole year and a half that we didn't have before with Logan will do wonders for Aaron," said Hawn. "It takes a lot of the sting and fear [out of] the second diagnosis because we're hopeful."