Hypothalamic-pituitary-adrenal Axis Multilocus Genetic Variation, Childhood Parenting and Adolescent Anxiety Symptoms: Evidence of Cumulative Polygenic Plasticity.

Research suggests that genetic variants that regulate the hypothalamic-pituitary-adrenal (HPA) axis function moderate the association between parenting and anxiety symptoms, but these studies have primarily focused on (i) individual genes with very small and unreliable effect and (ii) the role of mothers as opposed to fathers. Using a multilocus genetic profile score approach, the current study is the first to examine the moderation effect of HPA-axis multilocus genetic variants on the associations of both maternal and paternal parenting with adolescent anxiety symptoms. In a sample of Chinese Han adolescents (N = 772; 50.1% girls; Mage = 16.48 ± 1.40 years, range: 15-20 years), a theory-driven multilocus genetic profile score was computed by counting the numbers of alleles that were previously linked to heightened stress reactivity in six HPA-axis related genes. This HPA-axis related multilocus genetic profile score equivalently interacted with both maternal and paternal parenting in the prediction of adolescent anxiety symptoms. Consistent with cumulative polygenic plasticity hypothesis of differential susceptibility model, adolescents with more versus low alleles linked to heightened stress reactivity not only suffered more from poor maternal or paternal parenting quality, but also benefited more from high maternal or paternal parenting quality. However, none of the individual HPA-axis genes within this multilocus genetic profile score yielded a significant gene-by-environment (G × E) interaction when examined in isolation. The findings survived after internal replication analysis and a novel, valid influence statistic DFBETAS analysis, demonstrating the robustness of the results. The current study highlights the potential value of using a multilocus approach to understand G × E effects underlying anxiety symptoms and emphasizes the role of both mothers and fathers in such gene-parenting interactions, especially in Chinese families.