Women who make genetic contributors to autism and other neurological disorders may be more likely to experience disorders during pregnancy or exhibit behaviors that are themselves correlated with childhood autism, a new study finds.
The findings complicate research trying to find relationships between a child’s autism and their prenatal exposure. Genes that contribute to both autism and those exposures may explain such relationships.
“Research taking into account shared genetics is important to avoid potentially misleading conclusions and unnecessary parental guilt,” said lead researcher Alexandra Havdahlassociate professor of psychology at the University of Oslo in Norway.
A variety of disorders during pregnancy, such as medications or illnesses, can: predispose children to autism and other conditions, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, it remains unclear how big the influence of such prenatal influences is, as the genes that parents pass on to their children may also play a role in the development of these conditions.
But the c. tease aparta complex relationship between pregnancy-related factors and neurological disorders “may support new or less prioritized intervention targets,” Havdahl says.
For example, shared genetics probably explains why women who smoke during pregnancy are more likely to have a child with ADHD, earlier work has shown. Similarly, the apparent relationship between the autism and exposure to antidepressants during pregnancy can in fact reflect nothing more than their mother’s genetic predisposition to depression.
To unravel prenatal exposures of parental genetics, Havdahl and her colleagues researched data from 14,539 women and 14,897 men registered the Norwegian Mother, Father and Child Cohort Study. They analyzed the parents polygenic scores – similarities of genetic variants associated with certain traits – for autism, ADHD and schizophrenia. They also examined 37 maternal or paternal factors that may be linked to neurological disorders, including the use of prenatal vitamins or medications and health conditions such as depression, diabetes and preeclampsia.
The women’s polygenic scores for autism, ADHD and schizophrenia were associated with reports of depression and anxiety during pregnancy, as well as depression at other times in life, the researchers found. The belongs to women autism polygenic scores were also weakly linked to reports of migraines and urinary tract infections. The findings appeared on July 6 in JAMA Psychiatry.
“The fact that they detect these effects in such a small study is food for thought,” say Jakob Groveassociate professor of biomedicine at Aarhus University in Denmark, who did not participate in this study. “We need to follow a larger sample.”
Compared with polygenic scores for autism, elevated scores for ADHD were significantly associated with more pregnancy-related risk factors, such as younger age at delivery, higher risk of smoking during pregnancy, higher body mass index (BMI) before pregnancy, higher weight gain during pregnancy, lower risk of taking supplements (including folic acid) during pregnancy, asthma, and symptoms of depression or anxiety, with some weak evidence of an association with a higher risk of migraines and pain during pregnancy.
High polygenic scores for schizophrenia in the women were also associated with many pregnancy-related risk factors than for autism, such as increased risk of coffee consumption and cigarette smoking during pregnancy, lower BMI before pregnancy, higher weight gain during pregnancy, and greater chance of symptoms. of depression or anxiety during pregnancy and of taking medication for depression or anxiety, with some weak evidence of an association with a higher likelihood of taking supplements during pregnancy.
AWhile the scientists found little evidence of other associations between parental autism polygenic scores and pregnancy-related factors, such links may exist, Havdahl says.
“Our study had less ability to detect associations between autism polygenic scores and pregnancy factors than for ADHD and schizophrenia polygenic scores,” she says, due to the low heritability of many common autism-related genetic variations. “With larger genetic studies, this will be better understood.”
In the future, the team plans to further analyze the Norwegian mother, father and child cohort study to try to understand how genes and/or pregnancy-related factors influence specific traits, such as expressive language, social communication, repetitive behavior, attention and hyperactivity. . , says Havdahl. “In addition, we are planning studies to understand the social or environmental factors that contribute to adverse pregnancy exposures in women with neurodevelopmental disorders, to inform support research.”
More answers may also emerge as these kids get older, says Heather Volk, associate professor of mental health at Johns Hopkins University in Baltimore, Maryland, who did not participate in this work. That data set could reveal “how the genetic risk for these conditions during pregnancy may influence the risk of neurodevelopmental disorders in the offspring.”
With coverage by Laura Dattaro.