Pharmacogenomics in Africa

Abstract

The developed world has made significant advances in translating pharmacogenetics/genomics research into medical solutions that aim to personalize treatment that is based on a patients’ genetic status. Africa, on the other hand, has lagged behind in these advances, but recent developments are showing great potential for pharmacogenomics research and clinical applications on the continent. The genetic variability of African populations is proving an invaluable tool for understanding susceptibility and/or resistance to infectious diseases or noncommunicable diseases and the search for biomarkers for drug safety and efficacy. Studies on the polymorphism of genes that code for drug-metabolizing enzymes (CYP2B6, 2C9, 2C19, 2D6, FMO, NAT2, GSTT and GSTM) in nine major African ethnic groups (Yoruba, Ibo, Hausa, Kikuyu, Masaai, San, Luo, Venda, and Shona) showed genetic clustering of these populations distinct from that of Asian and of Caucasian populations. Clinical studies on the effect of the CYP2B6G516T variant on efavirenz concentrations were predictive of a dose reduction to a third of the standard dose in patient homozygous of the variant. This could have significant effects on the safe and efficacious use of this drug in Africa where 20% of the people are homozygous for this variant compared to about 5% in Caucasian and Oriental populations. We also found that CYP2C9 variants associated with dose optimization of warfarin in Caucasians are very rare in African populations. This has implication on the utility of commercial genetic diagnostic kits in use in Europe, which might not be applicable in African populations. Molecular evolution studies on the nine major ethnic groups and in comparison with data on Caucasian and Oriental populations using the Illumina chip with 600 K SNPs confirmed the genetic diversity of African populations and their distinct difference from other non-African populations. Though only a few genome-wide association studies (GWAS) have been done on common infectious diseases in Africa (malaria, TB, and HIV), interest in the scientific community to conduct such studies on noncommunicable disease in Africa will provide the scientific and technological impetus for genomic medicine research in Africa.KeywordsAfrican PopulationSlow AcetylatorsNoncommunicable DiseaseDose AlgorithmEfavirenz ConcentrationThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.