Educational attainment polygenic scores, socioeconomic factors, and cortical structure in children and adolescents

Genome-wide polygenic scores for educational attainment (PGS-EA) and socioeconomic factors, which are correlated with each other, have been consistently associated with academic achievement and general cognitive ability in children and adolescents. Yet, the independent associations of PGS-EA and socioeconomic factors with specific underlying factors at the neural and neurocognitive levels are not well understood. The main goals of this study were to examine the unique contributions of PGS-EA and parental education to cortical structure and neurocognitive skills in children and adolescents, and the associations among PGS-EA, cortical structure, and neurocognitive skills. Participants were typically developing 3- to 21-year-olds (53% male; N = 391). High-resolution, T1-weighted magnetic resonance imaging data were acquired, and cortical thickness (CT) and surface area (SA) were measured. PGS-EA were computed based on the EA3 genome-wide association study of educational attainment. Participants completed executive function, vocabulary, and episodic memory tasks. Higher PGS-EA and parental education were independently and significantly associated with greater total SA and vocabulary. Higher PGS-EA was significantly associated with greater SA in the left medial orbitofrontal gyrus and inferior frontal gyrus, which was associated with higher executive function. Higher parental education was significantly associated with greater SA in the left parahippocampal gyrus after accounting for PGS-EA and total brain volume. These findings suggest that education-linked genetics may influence SA in frontal regions, leading to variability in executive function. Associations of parental education with cortical structure in children and adolescents remained significant after controlling for PGS-EA, a source of genetic confounding.