Most children with autism become adults with autism, retaining the same relationship, school, work and communication issues, but a new study says some individuals diagnosed with an autism disorder in early childhood can outgrow the disorder.

“These children have a clear case of autism when they are young, but now do not meet the criteria for any autistic disorder," explained study author Deborah Fein, a professor of psychology at the University of Connecticut who researches autism. “Their social functioning is very good, they're all functioning in mainstream education with no support.”

One in 88 children is now affected by autism, which is the fastest-growing developmental disability in the U.S. Experts do not know why some children appear to outgrow the diagnosis as they age; there is no cure or medical test for autism.

In the new study, published online in the Journal of Child Psychology and Psychiatry Wednesday and supported by the National Institutes of Health, Fein and her colleagues looked at 34 "optimal outcome" individuals between 8 and 21 who were previously diagnosed with an autism disorder, but are now indistinguishable from their non-autistic peers. They showed no problems with language, communication, social interaction and “facial recognition," which can be difficult for individuals with autism.

"This is a story that's been around for a long time without very clear validation; the idea that some children could grow up to be adults without autism," Dr. Thomas R. Insel, director of the National Institutes of Mental Health told The Huffington Post.

The new study, Insel said, carefully tests whether those individuals ever truly had autism and whether they are now functioning like a non-autistic person. "In both cases," he said. "The answer is 'yes.'"

Fein and her colleagues are currently exploring why some children shed their autism diagnosis as they age, relying largely on parents' reports about the treatments they received. The researchers also use brain imaging to see whether their brains have normalized, or if they are somehow compensating for the disorder.

“At this point, all I can tell you is from my 40 years of clinical experience,” Fein said. "All of the kids I have personally seen who have moved off the [autism] spectrum have received some form of behavioral intervention.”

Numerous studies have found that behavioral interventions can be effective in improving things like social function and cognition in children with autism, but Fein cautioned that parents should keep the new study in perspective.

“This is not a common outcome,” she said. “We don't know what the percent is -- it's almost certainly under 25 percent, and it may be significantly lower than that.”

At this point, there is no way to predict which children will "lose" an autism diagnosis as they grow up and which children will not.

“I don't want people to see this story and say, ‘My goodness! Where have I failed because my child didn’t have an ‘optimal outcome?’" echoed Insel. “What we're interested in doing is helping parents help their kids grow up to be adults who can really participate in the world -- who can work and have a family and a life -- whether they have the symptoms of autism or not.”