Background: Inter-individual differences in response to medications are known to have a strong genetic component. Pharmacogenomics involves the study of this genetic contribution and aims to improve drug safety and efficacy by predicting optimal treatment regimes on an individual basis. Research has identified several genes that influence either response to medications or adverse drug reactions. By leveraging publically available genomic data, the spectrum of genetic variation in such genes can be extensively investigated and can be used to inform the clinical implementation of pharmacogenomic tests.

Methods: Genes included in this study were selected based on relevance to pharmacogenomics according to the PharmGKB database. Genetic variants in these regions of interest were extracted from the 1000 Genomes Project sequencing data for 2504 samples from 26 global populations. Variants were subsequently annotated using the Ensembl Variant Effect Predictor and analysed in further detail utilising the program, VCFtools and the software environment, R.

Results: A total of 12050 genetic variants were identified in the 62 genes that met inclusion criteria. Pharmacogenomic variation tended to be most similar within continental populations and all samples carried a median of five clinical variants with a high level of scientific evidence. Genetic variants that would severely impair protein function were found in genes associated with adverse drug reactions such as vincristine-induced peripheral neuropathy, methotrexate-induced mucositis and cisplatin-induced ototoxicity.

Conclusion: The results of the current study have the potential to inform future pharmacogenomic studies and ultimately improve disease. For example, the current data can be incorporated into research conducted by the Canadian Pharmacogenomics Network for Drug Safety, which is conducting several genomic studies of adverse drug reactions in pediatric and adult patients.