New findings as to the origin of autism

Researchers have found areas of disruption in the brains of young children with autism spectrum disorder (ASD), indicating that ASD originates sometime early in the prenatal period, according to a new small explorative study.

Rich Stoner, PhD, from the University of California’s Autism Center of Excellence in San Diego, and colleagues conducted postmortem examinations on sample brain tissue from 11 children with autism and 11 children without. All the children were aged 2 to 15 years.

The study, which was partially funded by the National Institute of Mental Health (NIMH), turned up patches of abnormal cell arrangement in the prefrontal and temporal cortexes in 10 of the 11 children diagnosed with ASD and in only 1 of the children without autism. The researchers describe the regions as measuring 5 mm to 7 mm in length, penetrating multiple cortical layers, and having fewer cells expressing certain markers that are normally present, as well as having “decreased expression of certain autism candidate genes.”

They say that the location of the patches in the outermost structure of the brain corresponds with the functions that are disturbed in autism, including social and emotional aspects and communication and language disruptions.

The NIMH explains that the patchy-rather than diffuse-nature of the disorganized regions may help explain why early intervention helps many youngsters with ASD improve. The developing brain learns to rewire by sidestepping the damaged regions and relying on neighboring areas to pick up the slack.

The investigators report that their findings point to “an early prenatal origin of autism” or to a prenatal process that predisposes a child to the condition. Exactly what the mechanism is remains a mystery. 

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