Autism May Begin in the Womb: Brain Abnormalities Spotted Before Birth

About 1 in 68 children in the United States have some form of autism-spectrum disorder (ASD). The cause for the disease is relatively unknown, but scientists are certain that genetics play a role, as a recent NIH-funded study has shown.

Published in the New England Journal of Medicine, "Patches of Disorganization in the Neocortex of Children with Autism" suggests that the brain abnormalities associated with autism can be traced back to before a child is born. The researchers observed focal patches of abnormal brain neurons in children with autism and found that the clustered neurons in the prefrontal cortex may occur during prenatal development.

The study examined the brains of children that were donated to science following their passing. Tissue samples from brain regions that regulated social functioning, emotion, and communication revealed clusters of disorganized brain cells in 10 of the 11 brains of autistic children. The researchers believe that these defects most likely occurred during the second or third trimesters of pregnancy. They also examined 11 brains from children without the disorder, also donated to science.

Disorganization of the brain's cortex is a likely culprit of ASD. This area of the brain is critical for learning and memory. It contains six layers with each one containing different types of brain cells. They found that the disruption of these layers is likely associated with autism.

"In the children with autism there are patches in which specific cells in specific layers seem to be missing," said Eric Courchesne, one of the paper's authors, in this NPR article.

This research adds to the current arsenal of evidence that scientists have supporting the fact that autism starts in the womb. Although this study is new, the researchers believe that a larger study of this kind would be helpful in arriving at a more definitive answer. It's possible that various combinations of genes that contribute to autism could present similar neuron disorganization.

To read more about the ASD study published in the NEJM, visit this CBS News article.