Genetic Factors in Schizophrenia Risk

Recent findings Multiple and variable genetic and environmental factors interact to influence the risk of schizophrenia. Both rare variants with large effect and common variants with small effect contribute to genetic risk of schizophrenia, with no indication for differential impact on its clinical features. Accumulating evidence supports a genetic architecture of schizophrenia with multiple scenarios, including additive polygenic, heterogeneity, and mixed polygenic-heterogeneity. The epigenetic mechanisms that mediate gene– environment (GxE) interactions provide a framework to incorporate environmental factors into models of schizophrenia risk. Environmental pathogens with small effect on risk have robust effects in the context of family history of schizophrenia. Hence, genetic risk for schizophrenia may be expressed in part as sensitivity to environmental factors.