Study Finds Subset of Schizophrenia Genes Linked to Placenta

In Nature Communications, researchers at Johns Hopkins University and other centers in the US and Italy share findings linking schizophrenia causal candidate risk genes to placental tissue. The team initially turned to RNA sequencing and genotyping to assess 147 placental tissues collected through the Rhode Island Child Health Study, representing individual infants born at term without congenital abnormalities, chromosomal conditions, or pregnancy complications. With a subsequent transcriptome-wide association study, Mendelian randomization analysis, and expression quantitative trait locus-based colocalization, together with analyses on 166 fetal brain samples, the authors narrowed in on a set of 139 schizophrenia risk genes with ties to the placenta, including causal gene candidates from placental growth, nutrient-sensing, protein synthesis, and trophoblast invasiveness pathways. "[O]ur findings, while not detracting from the importance of gene expression in brain for schizophrenia risk, reveal a larger picture that includes placenta: both placenta and brain might contribute to early and reversible trajectories of risk for the disorder, but most research on brain development has been exclusively focused on the brain," they note. "Neglecting the investigation of placental mechanisms of risk may miss relevant opportunities for prevention."