Genomic Ancestry, CYP2D6, CYP2C9, and CYP2C19 Among Latin Americans.

We present the distribution of CYP2D6, CYP2C9, and CYP2C19 variants and predicted phenotypes in 33 native and admixed populations from Ibero-America (n > 6,000) in the context of genetic ancestry (n = 3,387). Continental ancestries are the major determinants of frequencies of the increased-activity allele CYP2C19*17 and CYP2C19 gUMs (negatively associated with Native American ancestry), decreased-activity alleles CYP2D6*41 and CYP2C9*2 (positively associated with European ancestry), and decreased-activity alleles CYP2D6*17 and CYP2D6*29 (positively associated with African ancestry). For the rare alleles, CYP2C9*2 and CYPC19*17, European admixture accounts for their presence in Native American populations, but rare alleles CYP2D6*5 (null-activity), CYP2D6-multiplication alleles (increased activity), and CYP2C9*3 (decreased-activity) were present in the pre-Columbian Americas. The study of a broad spectrum of Native American populations from different ethno-linguistic groups show how autochthonous diversity shaped the distribution of pharmaco-alleles and give insights on the prevalence of clinically relevant phenotypes associated with drugs, such as paroxetine, tamoxifen, warfarin, and clopidogrel.

Interethnic Variability in CYP2D6, CYP2C9, and CYP2C19 Genes and Predicted Drug Metabolism Phenotypes Among 6060 Ibero- and Native Americans: RIBEF-CEIBA Consortium Report on Population Pharmacogenomics.

Pharmacogenetic variation in Latin Americans is understudied, which sets a barrier for the goal of global precision medicine. The RIBEF-CEIBA Network Consortium was established to characterize interindividual and between population variations in CYP2D6, CYP2C9, and CYP2C19 drug metabolizing enzyme genotypes, which were subsequently utilized to catalog their "predicted drug metabolism phenotypes" across Native American and Ibero American populations. Importantly, we report in this study, a total of 6060 healthy individuals from Ibero-America who were classified according to their self-reported ancestry: 1395 Native Americans, 2571 Admixed Latin Americans, 96 Afro-Latin Americans, 287 white Latin Americans (from Cuba), 1537 Iberians, and 174 Argentinean Ashkenazi Jews. Moreover, Native Americans were grouped into North-, Central-, and South Amerindians (from Mexico, Costa Rica, and Peru, respectively). All subjects were studied for the most common and functional CYP2D6, CYP2C9, and CYP2C19 allelic variants, and grouped as genotype-predicted poor or ultrarapid metabolizer phenotypes (gPMs and gUMs, respectively). Native Americans showed differences from each ethnic group in at least two alleles of CYP2D6, CYP2C9, and CYP2C19. Native Americans had higher frequencies of wild-type alleles for all genes, and lower frequency of CYP2D6*41, CYP2C9*2, and CYP2C19*17 (p < 0.05). Native Americans also showed less CYP2C19 gUMs than the rest of the population sample. In addition, differences within Native Americans (mostly North vs. South) were also found. The interethnic differences described supports the need for population-specific personalized and precision medicine programs for Native Americans. To the best of our knowledge, this is the largest study carried out in Native Americans and other Ibero-American populations analyzing CYP2D6, CYP2C9, and CYP2C19 genetic polymorphisms. Population pharmacogenomics is a nascent field of global health and warrants further research and education.

CYP2D6 -1584C>G promoter polymorphism and debrisoquine ultrarapid hydroxylation in healthy volunteers.

BACKGROUND & AIM: The CYP2D6 -1584C>G polymorphism (rs1080985) has been identified as a major factor for CYP2D6 expression and function, with the mutant -1584G promoter type being consistently associated with significantly greater expression than -1584C. It may therefore be associated with ultrarapid metabolism. The objective of the present study was to explore the relationship between the CYP2D6 -1584C>G polymorphism and the debrisoquine metabolic ratio in healthy volunteers in order to evaluate its potential impact on the ultrarapid CYP2D6 hydroxylation capacity. MATERIALS & METHODS: The CYP2D6 -1584C>G polymorphism was analyzed in 320 unrelated healthy individuals who were previously phenotyped for debrisoquine hydroxylation. RESULTS: The metabolic ratio (log10 mean ± standard deviation) of individuals with the -1584G allele was lower than that of individuals with the -1584C allele for carriers of one active CYP2D6 gene (-0.13 ± 0.33 and 0.17 ± 0.52, respectively; p < 0.05) or two active CYP2D6 genes (-0.32 ± 0.39 and -0.20 ± 0.44, respectively; p < 0.05). CONCLUSION: The presence of the -1584G allele in the promoter region of the CYP2D6 gene was related to a high CYP2D6 hydroxylation capacity.