Direct Genetic Effects Dominate Pediatric Anthropometric Traits, Genetic Nurture Shows Limited Influence

A new study published in Human Molecular Genetics reveals that direct genetic effects primarily determine pediatric anthropometric traits such as height, body mass index (BMI), and bone mineral density (BMD) in children. The research, which analyzed a multi-ethnic Dutch pediatric cohort, indicates that "genetic nurture" – the indirect influence of parental genes through environmental factors – has a limited impact during formative years. The findings challenge previous assumptions about the extent of parental environmental influence on these physical characteristics.Genetic nurture refers to how parental genetic variants can indirectly shape a child's traits by influencing the environment they provide. Anthropometric traits, including height, BMI, and BMD, are crucial indicators of child health and development. Understanding the genetic and environmental contributions to these traits is vital for public health and personalized medicine.The study found statistically significant direct genetic effects (DGE) for all three traits across ages six, nine, and thirteen. Specifically, 71% to 77% of the BMI variance explained by polygenic risk scores could be attributed solely to direct genetic inheritance. This highlights the strong influence of a child's own inherited genes on their physical development.Indirect genetic effects (IGE) were found to be significant only for BMI at ages nine and thirteen, with minor magnitude. For height and bone mineral density, IGE estimates did not reach statistical significance at any age. Researchers also observed no significant differences in the indirect contributions from maternal and paternal genes, contrasting with some prior studies that suggested stronger maternal nurturing effects for other traits.Conducted on 4,488 probands with genetic data from the Generation R Study, the longitudinal research involved repeated measurements at ages six, nine, and thirteen. The team utilized polygenic risk scores (PRSs) and advanced imputation methods to differentiate between direct genetic transmission and indirect environmental influences. The study's methodology aimed to provide a clearer picture of how genes and environment interact in early development.These insights suggest that while environmental factors are undoubtedly important, the direct genetic blueprint inherited by a child plays a predominant role in their anthropometric development. The authors note that understanding these distinct genetic effects can refine the use of polygenic risk scores in clinical settings, potentially leading to more accurate disease screening and personalized interventions for conditions like obesity.