About 1 in 6 children with autism have been asked to leave a child care or preschool setting, new research finds, and the experience has long-lasting consequences.

In a study looking at more than 200 kids with autism ages 4 to 7, parents reported that 16% had been expelled before reaching elementary school, most often for behavior issues.

“It’s shocking,” said Jan Blacher, a professor at the University of California, Riverside and the University of California, Los Angeles who led the study published recently in the journal Exceptional Children. “These little kids were asked to leave school because they demonstrated behaviors directly related to their autism. So, they were being expelled from preschool for the very problems that they needed school for.”

Children were a little over age 3, on average, when they were kicked out of their child care program, the study found. The expulsions were more common in private versus public programs.

The researchers noted that many of the children who were turned away from school had not been identified as having a disability.

“That suggests to us that it never occurred to the teachers to refer them for assessment,” Blacher said. “So, part of it is a lack of teacher awareness of the prevalence of autism, and how it manifests in a very young age. Had they understood autism, they might have been inspired to deal with it, and say, ‘Maybe I should have this child assessed.'”

By the time they reached kindergarten, the study found that kids who had been asked to leave school during their early years experienced more conflict with their teachers and were more dependent on them, among other challenges.

“These are very young children who have no idea why they are being asked to leave school. And it leaves the kids in kind of a quandary,” Blacher said.