There's been a lot of debate as to what causes autism to develop in children. Now, though, researchers may have their answer. Scientists have discovered new evidence that shows autism begins during pregnancy.
In order to better understand autism development, the researchers analyzed 25 genes in post-mortem brain tissue with and without autism. These genes included ones that served as biomarkers for brain cell types in different layers of the cortex, ones implicated in autism and several control genes.
"Building a baby's brain during pregnancy involves creating a cortex that contains six layers," said Eric Courchesne, one of the researchers, in a news release. "We discovered focal patches of disrupted development of these cortical layers in the majority of children with autism."
So what does this mean exactly? It turns out that babies with autism have brains that don't develop properly while still in the womb. During early brain development, each cortical layer develops its own specific types of brain cells, each with specific patterns of brain connectivity that perform different roles when it comes to processing information. Yet children with autism don't have key genetic markers in brain cells in multiple layers.
That's not all that the researchers found, though. They also noted that the defects occurred in patches across the cortex.
"The finding that these defects occur in patches rather than across the entirety of cortex gives hope as well as insight about the nature of autism," said Courchesne in a news release.
The new findings reveal that autism may develop before a child is born rather than be a product of environmental factors. It also reveals a bit more about the nature of the condition itself, which could allow scientists to develop treatments in the future.
The findings were published in the New England Journal of Medicine.
