About 9% of children with childhood-onset schizophrenia have been found to have genetic abnormalities, Dr. Rapoport explained. When children with multiple copies or deletions of key genes are counted, the proportion with possible genetic markers rises to 36%.
Moreover, many of the genes also are implicated in autism. Both conditions are associated with ahead-of-normal brain development, she said, and the timing of certain milestones might determine which of these or other disorders develops. Of note, three children referred to the team as possibly having childhood-onset schizophrenia subsequently developed bipolar disorder instead.
“I think the world is going to be stood on its head diagnostically when these things get sorted out,” Dr. Rapoport said, estimating that as many as 50% of children with early neurodevelopmental abnormalities could have copy number variants.