A different form of genetic convergence is related to the microRNA-encoding gene MIR137, another locus which is genome-wide significant for schizophrenia. MicroRNAs are non-protein-coding genes, whose RNA products bind to the 3’ region of specific mRNAs and inhibit their translation. Several of the mRNA targets of MIR137 (determined empirically, or predicted bioinformatically) are also GWAS schizophrenia genes (including TCF4, ZNF804A, and CACNA1C; Kim et al., 2012; Kwon et al., 2013; Wright et al., 2013; see also Boudreau et al., 2014), suggesting that there may be functional impairment of a network of MIR137-regulated genes in schizophrenia. However, the evidence is limited, and it is not even certain that the signal at this locus is attributable to MIR137 and not to the adjacent DYPD gene – an illustration of the difficulty noted earlier moving from locus to gene (Schizophrenia Working Group of the Psychiatric Genomics Consortium, 2014).
