In conclusion, we carried out a GWA analysis of >300 000 SNPs and 48 000 expression phenotypes determined in a cohort of 149 human surgical liver samples obtained from Caucasian donors to identify genetic loci associated with quantitative changes in gene expression. A subset of 95 significant genotype–phenotype relationships, which was classified as ADME or ADME-related may be of particular relevance for drug disposition and toxicity. Detailed comparison between this study and the similar Seattle study demonstrated that quantitative trait loci are difficult to reproduce because of a number of technical and statistical reasons, and that several studies are required to discover the full extent of genetic determination in quantitative traits. Follow-up studies to elucidate the causal variants and their biological and pharmacological relevance should therefore concentrate on the validated results.
