Brain RNA and genomic DNA samples were obtained from the Stanley Medical Research Institute (SMRI). This collection comprises 3 diagnostic groups, each with 35 samples: healthy control, bipolar disorder and schizophrenia. All experiments were done after the specimen code was broken and they were thus unblinded. RNA samples originated from the dorsolateral prefrontal cortex. Of these, 101 samples provided sufficient RNA for reverse transcription (Transcriptor First Strand cDNA Synthesis kit with oligo-dT priming, Roche Applied Science, Indianapolis, IN) and subsequent real-time PCR analysis. We amplified PBRM1 mRNA with a primer pair common to all known RefSeq transcript variants (Eurofins MWG operon, Huntsville, AL) and a FAM-labeled probe (Roche Applied Science Universal Probe Libraray probe # 41). No known SNPs overlapped with primer or probe sequences (Supplementary Figure 2). For normalization, we used a pre-designed endogenous control assay interrogating PGK1 (Applied Biosystems, Foster City, CA; catalog number 4333765F, FAM-labeled). Reactions were carried out in triplicate in a 384-well LightCycler 480 (Roche Applied Science) in reaction volumes of 8 uL, with 5 ng of reverse-transcribed RNA, 1x final concentration of Roche LightCycler
