Pharmacologically relevant eQTLs were extracted based on a comprehensive compilation of 682 non-overlapping ADME genes, resulting in 89 cis- and 6 trans-associations. Similarly to the entire eQTL set, only 3 of the 95 ADME eQTLs were exactly replicated, and another 10 eQTLs were shown to be replications by LD. More detailed information on all replicated associations is presented in Supplementary Results and Discussion. Several of the unique ADME gene associations of our study concern known polymorphically expressed genes, including UGT1A1,44 CYP4F1248 and GST subforms M3, O2 and T1. Although these were not identified in the Seattle study, they likely relate to these biologically confirmed polymorphisms. Except for CYP3A5 and CYP4F12, no other CYP genes were present among the identified eQTLs. The failure to detect the well-known polymorphic CYPs (for example, 2A6, 2B6, 2C19, 2D6) may be explained by the mechanisms involved which often include complex splicing events which may not be detectable by the microarray probes.49
