Some young children accurately diagnosed as autistic lose their symptoms and their diagnosis as they get older, say US researchers.
The findings of the National Institutes of Health study of 112 children appears to challenge the widely held belief that autism is a lifelong condition.
While not conclusive, the study, in the Journal of Child Psychology and Psychiatry
, suggests some children might possibly outgrow autism.
But experts urge caution.
Much more work is needed to find out what might explain the findings.
Dr Deborah Fein and her team at the University of Connecticut studied 34 children who had been diagnosed with autism in early childhood but went on to function as well as 34 other children in their classes at school.
On tests - cognitive and observational, as well as reports from the children's parents and school - they were indistinguishable from their classroom peers. They now showed no sign of problems with language, face recognition, communication or social interaction.