Women who experience stress during pregnancy and have a stress-sensitive gene are more likely to give birth to a child with autism, researchers have discovered.
The finding could be a step toward helping identify women who have greater risks for having children with autism when exposed to stressors during a specific time window during their pregnancy.
“Autism was thought to be largely a genetic disorder, but previous research has shown that environmental influences such as stress can play an important role in the development of the condition,” says David Beversdorf, associate professor of radiology, neurology, and psychological sciences at the University of Missouri.
“We know that some mothers who experience significant levels of stress don’t have children with autism, but others do. To help understand why, we studied a gene that is known to affect stress and found a link between it and the development of autism with exposure to stress.”
For a new study, published in Autism Research, scientists looked at two groups of mothers of children with autism spectrum disorder. The mothers were surveyed about stress during their pregnancy, such as loss of a job, moving, or divorce. The mothers’ blood was tested for a variation of the stress-sensitive gene known as 5-HTTLPR, which regulates the neurotransmitter serotonin in the nervous system. When a variation of the gene is present, the availability of serotonin is altered, causing an increased reaction to stress.
In both groups, mothers of children with autism who have the variation of the stress-sensitive gene reported experiencing more stress during the end of the second and the beginning of the third trimester of pregnancy, compared to mothers who did not carry the altered gene.
“Though this was an observational study and future confirmation of this finding is needed, it’s possible we could, one day, identify women who may be at a greater risk of having a child with autism when exposed to stress,” Beversdorf says.
“More research is needed to understand the mechanisms of how this gene-stress interaction works, but hopefully this could someday help prevent some cases of autism.”
Other researchers from the University of Missouri and from Queen’s University, Central Methodist University, and Massachusetts General Hospital for Children are coauthors of the study.
Source: University of Missouri