AIMS: Polymorphisms of genes involved in the pharmacokinetic and pharmacodynamic 
processes underlie the divergent drug responses among individuals. Despite some 
successes in identifying these polymorphisms, the candidate gene approach 
suffers from insufficient gene coverage whereas the genome-wide association 
approach is limited by less than ideal coverage of SNPs in some important genes. 
To expand the potential of the candidate approach, we aim to delineate a 
comprehensive network of drug-response genes for in-depth genetic studies.
MATERIALS & METHODS: Pharmacologically important genes were extracted from 
various sources including literatures and web resources. These genes, along with 
their homologs and regulatory miRNAs, were organized based on their 
pharmacological functions and weighted by literature evidence and confidence 
levels. Their coverage was evaluated by analyzing three commercial SNP chips 
commonly used for genome-wide association studies: Affymetrix SNP array 6.0, 
Illumina HumanHap1M and Illumina Omni.
RESULTS: A panel of drug-response genes was constructed, which contains 923 
pharmacokinetic genes, 703 pharmacodynamic genes and 720 miRNAs. There are only 
16.7% of these genes whose all known SNPs can be directly or indirectly (r(2) > 
0.8) captured by the SNP chips with coverage of more than 80%. This is possibly 
because these SNPs chips have notably poor performance over rare SNPs and miRNA 
genes.
CONCLUSION: We have compiled a panel of candidate genes that may be 
pharmacologically important. Using this knowledgebase, we are able to 
systematically evaluate genes and their variants that govern an individual's 
response to a given pharmaceutical therapy. This approach can serve as a 
necessary complement to genome-wide associations.