Anecdotal evidence suggests onset of autism occurs somewhere between 1-2 years old, but a new study places the critical point early in embryo development, before there are any mature nerve cells whatsoever. Researchers found gene-activity changes come before any visible differences in neurons.

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Anecdotal evidence suggests onset of autism occurs somewhere between 1-2 years old, but a new study places the critical point early in embryo development, before there are any mature nerve cells whatsoever. Researchers found gene-activity changes come before any visible differences in neurons.