Abstract
Schizophrenia is a complex psychiatric disorder with clinical and genetic heterogeneity. Schizophrenia shows multifactorial inheritance with a heritability of 80%. It is suggested the involvement of disorder‐specific genetic factors and genetic factors shared with other psychiatric disorders in the pathogenesis of schizophrenia. Furthermore, not only genetic factors but also environmental factors contribute to the pathogenesis of schizophrenia. As for genetic factors, a large number of genetic polymorphisms are involved in the development of schizophrenia. Several environmental factors may also influence methylation patterns, and have an impact on development and pathogenesis. Overall, it has been suggested that schizophrenia may be caused by gene‐environment interactions, but the mechanisms are not yet fully understood. The polygenic risk score (PRS) and methylation risk score (MRS) are methods to assess an individual’s risk of disorder based on the accumulation of genetic polymorphisms and DNA methylation patterns at numerous loci across the whole genome, respectively. These indices are independent genetic markers, and both PRS and MRS are expected to contribute to the risk of schizophrenia.
