Autism numbers not what they used to be.

The largest U.S. study of childhood autism to date now finds one in 150 have the disorder which is higher than previously thought.

College Oaks Elementary is one school where teachers work hard to help children with autism learn and grow.  On this visit, little girls Elizabeth and Alyssa are fascinated with the video camera I've brought to take their picture and interview their teacher. The two six year olds have been diagnosed with autism and their teacher at College Oaks is Heather Gibson.  She says, "Everyday is a challenge and a reward at the same moment. They're a joy to have, they really are."

Gibson and other teachers and aides received training from Dr. Cathy Pratt, an internationally known speaker and writer, whose expertise is in special education and public policy. Pratt says, "We used to believe that the incidence of autism was one in 5,000 ten to fifteen years ago and now the Centers for Disease Control just came out with a study that the incidence is one in 150 and that this disability that used to be so uncommon is now much more common than disabilities like childhood cancer or much more common than Down's Syndrome."

Pratt says the greater incidence of autism underscores the importance of more research to find a cause.

"We know right now that there's a genetic predisposition towards autism. But then, what we have to figure out is what is the trigger that causes that genetic predisposition to go off. And some of the things that they're looking at are of course the very controversial issues around the vaccinations, but now there's starting to be research around environmental conditions and different toxins that could be triggering autism to occur."

She emphasizes the importance of early and ongoing intervention for children like Alyssa and Elizabeth.

For more information on autism and the study released by the CDC click here.