Ren H, Meng Y, Zhang Y, et al. - Researchers aimed at examining the potential of combining the transcription output of the core gene underlying the commonality of psychiatric disorders with a clustering algorithm to redefine psychiatric disorders. Per findings, there appeared a correlation of an extended MHC region with the common factor of schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) at the level of genomic significance, with rs7746199, a cis-eQTL to the gene ZNF391, pinpointed as a potential causal variant driving the signals in the region. Three biotypes emerged after assessing gene expression pattern of ZNF391 in the brain, independent of disorder. Significantly different performance of the three biotypes was noted in working memory and they demonstrated different gray matter volumes in the right inferior frontal orbital gyrus (RIFOG), with a partial causal pathway arising from ZNF391 to RIFOG to working memory. Findings are suggestive of the potential of a trans-diagnostic, top-down approach in determining the commonality of psychiatric disorders.