cells Review Novel Approaches for Identifying the Molecular Background of Schizophrenia Arkadiy K. Golov 1,2,*, Nikolay V. Kondratyev 1 , George P. Kostyuk 3 and Vera E. Golimbet 1 1 Mental Health Research Center, 34 Kashirskoye shosse, 115522 Moscow, Russian;
[email protected] (N.V.K.);
[email protected] (V.E.G.) 2 Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova Street, 119334 Moscow, Russian 3 Alekseev Psychiatric Clinical Hospital No. 1, 2 Zagorodnoye shosse, 115191 Moscow, Russian;
[email protected] * Correspondence:
[email protected] Received: 5 November 2019; Accepted: 16 January 2020; Published: 18 January 2020 Abstract: Recent advances in psychiatric genetics have led to the discovery of dozens of genomic loci associated with schizophrenia. However, a gap exists between the detection of genetic associations and understanding the underlying molecular mechanisms. This review describes the basic approaches used in the so-called post-GWAS studies to generate biological interpretation of the existing population genetic data, including both molecular (creation and analysis of knockout animals, exploration of the transcriptional effects of common variants in human brain cells) and computational (fine-mapping of causal variability, gene set enrichment analysis, partitioned heritability analysis) methods. The results of the crucial studies, in which these approaches were used to uncover the molecular and neurobiological basis of the disease, are also reported. Keywords: schizophrenia; GWAS; causal genetic variants; enhancers; brain epigenomics; genome/epigenome editing 1. Introduction Schizophrenia is a severe mental illness that affects between 0.5% and 0.7% of the human population [1]. Both environmental and genetic factors are thought to be involved in its pathogenesis, with genetic factors playing a key role in disease risk, as the heritability of schizophrenia is estimated to be 70–85% [2,3].