A new study, published in the journal Molecular Psychiatry, shows that parents' genetic traits—especially those of mothers—can influence how their children’s DNA is expressed, even when those traits are not directly inherited. This happens through so-called genetic nurturing: genetic traits of the parents that influence the child’s development via the environment.
The researchers, led by behavioral geneticists from Vrije Universiteit Amsterdam, discovered that children's DNA undergoes chemical modifications at specific sites (known as DNA methylation) in ways that are linked to the genetic traits of their parents. These methylation changes are not directly passed on to the next generation, but they can influence the child’s brain development, immune system, and growth.
Key findings:
- Children's DNA showed changes in DNA methylation levels that were associated with their parents’ genetic scores for traits such as schizophrenia, educational attainment, BMI, and height.
- The strongest associations were found with schizophrenia: 16 specific DNA sites (known as CpG sites) were linked to the parental genetic predisposition for this disorder. In nearly 94% of cases, this was traced back to the mother.
- Overall, maternal genetic influences were found to affect children's DNA methylation more often than paternal ones. This may be due to prenatal influences, in line with the Developmental Origins of Health and Disease (DOHaD) theory, or early parenting.
- Some of the methylation changes identified are related to genes important for brain development and the immune system—such as PTPRG, PCDH1, and CCHCR1—which may be linked to the risk of mental disorders like schizophrenia.
Why is this important?
This study is the first to systematically investigate how indirect genetic influences from parents affect gene expression in their children. Using data from over 1,500 children and their parents, the research shows that parental genes can shape a child’s development—even if those genes are not directly inherited.
“These results give insight into how parental genes influence the biological development of children via the environment,” the study’s authors say. “This can help us better understand how diseases develop and how development unfolds.”
About the study
The research was conducted by scientists from Vrije Universiteit Amsterdam, the University of Helsinki, and Avera McKennan Hospital. They analyzed DNA from cheek swabs of children and linked this information to genetic profiles of their parents, who are participants in studies from the Netherlands Twin Register.
Lead researcher Professor Dorret Boomsma says: “Once again, we see how significant maternal influences are on brain development and the early life environment.” Fiona Hagenbeek, first author of the article, adds: “This study opens new doors for exploring how genetic nurturing shapes biological processes in children. It fills in a missing piece of the nature-versus-nurture puzzle.”