Aim: The indigenous Arab population is underrepresented in genomic studies and the landscape of actionable pharmacogenomic variants among Arab breast cancer patients remains unclear. Materials & methods: Exome sequencing was performed on 220 unselected Arab female breast cancer patients and germline variants in CYP2D6 and DPYD were profiled using a deep learning method. Results: In total, 13 (5.9%) patients had clinically actionable results and 56 (25.5%) carried an allele in DYPD or CYP2D6 with unknown impact on drug metabolism. In addition, four unique novel missense variants were discovered, including one in CYP2D6 (p.Arg64Leu) with high predicted pathogenicity. Conclusion: A nontrivial subset of Arab breast cancer patients can potentially benefit from pretreatment molecular profiling, and further study is needed to improve characterization of the pharmacogenomic landscape.
Keywords: Arab population; CYP2D6; DPYD; breast cancer; drug metabolism; exome sequencing; fluoropyrimidines; pharmacogenomics; tamoxifen.