Washington: A new study has revealed that autism begins during pregnancy.
The Researchers at the University of California, San Diego School of Medicine and the Allen Institute for Brain Science, who analyzed 25 genes in post-mortem brain tissue of kids with and without autism, found that there were focal patches of disrupted development of these cortical layers in the majority of children with autism.
Eric Courchesne, professor of neurosciences and director of the Autism Center of Excellence at UC San Diego, said that building a baby's brain during pregnancy involves creating a cortex that contains six layers and these included genes that serve as biomarkers for brain cell types in different layers of the cortex, genes implicated in autism and several control genes.
The study found that in the brains of children with autism, key genetic markers were absent in brain cells in multiple layers.
Courchesne said that this defect indicates that the crucial early developmental step of creating six distinct layers with specific types of brain cells had been disrupted.
The brain regions most affected by focal patches of absent gene markers were the frontal and the temporal cortex, possibly illuminating why different functional systems are impacted across individuals with the disorder.
According to the scientists, such patchy defects, as opposed to uniform cortical pathology, may help explain why many toddlers with autism show clinical improvement with early treatment and over time.
The study was published online in the New England Journal of Medicine.