Autism may begin in utero, according to a study of postmortem brain tissue from children with and without autism published online ahead of print March 27 in the New England Journal of Medicine.
The findings imply that layer formation and layer-specific neuronal differentiation are dysregulated during prenatal development. The study also suggests that early recognition and treatment of autism may allow the developing brains of autistic children to construct alternative brain pathways around the patchy defects in the cortex. The result could be improved social functioning and communication, the researchers theorized.
Researchers used gene expression to examine cellular markers in each of the cortical layers, as well as genes that are associated with autism. Markers for several layers of the cortex were absent in the brain tissue of 10 of 11 (91%) children with autism and in one of 11 (9%) control children. The areas of disorganization were seen in multiple cortical layers, with most abnormal expression noted in layers 4 and 5 and focal disruption of cortical laminar architecture as patches that were 5 to 7 mm long.
—Mary Jo M. Dales