To determine whether there is tissue specificity regarding the contribution of mQTLs to disease, we also assessed the level of overlap between mQTLs in cerebellum and in LCLs among the top associations with Bipolar Disorder. We compared our findings with the (publicly available) results from a recent association analysis of methylation levels 23 in the HapMap lymphoblastoid cell lines to look for evidence of cross-tissue common regulators. The methylation profiles for these cell lines were assayed using the same platform as our human cerebellum samples. We found among the top SNP associations (p < 0.001) from the WTCCC study no overlap between mQTLs identified in brain with the cis mQTLs identified in the LCLs. Indeed, none of the mQTLs identified in LCLs overlapped with the most significant SNPs (p < 0.001) from the WTCCC study.
