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.

Pharmacogenetics and ethnicity: relevance for clinical implementation, clinical trials, pharmacovigilance and drug regulation in Latin America.

Congress of Pharmacogenetics and Personalized Medicine. Ethnicity, clinical implementation and regulatory environment (MESTIFAR 2016 Quito) Quito, Ecuador, 19-21 May 2016. The Ibero-American Network of Pharmacogenetics and Pharmacogenomics (RIBEF) was created in 2006 with the main aim of promoting personalized medicine and collaborative pharmacogenetics research in Spanish- and Portuguese-speaking countries in America and the Iberian Peninsula. The final goal of this initiative was the inclusion of Latin American populations that may benefit from the implementation of personalized medicine in drug therapy. Several initiatives have been promoted including the MESTIFAR project, which aimed to analyze the ethnicity, genotype and/or metabolic phenotype in Ibero-American populations. To date, 6060 healthy volunteers have been analyzed; among them, 2571 were admixed, 1824 were Caucasians, 1395 were Native Americans, 174 were Jews and 96 were Afro-descendants. Due to the large genetic variability within Latin Americans, ethnicity may be a relevant factor for the clinical implementation of personalized medicine. Moreover, the present status of clinical implementation and the future perspectives of pharmacogenetics, pharmacovigilance and clinical trials for drug regulation in Latin America compared with the EMA-Pharmacogenomics Working Party and the US FDA initiatives were analyzed.

Population pharmacogenetics of Ibero-Latinoamerican populations (MESTIFAR 2014).

MESTIFAR 2014 28-30 November 2014, Panama City, Panama The CEIBA consortium was created within the Ibero-American network of Pharmacogenetics (RIBEF) to study population pharmacogenetics. The current status of these initiatives and results of the MESTIFAR project were analyzed in Panama, 28-30 November 2014. The MESTIFAR project focused on studying CYPs genetic polymorphisms in populations of different ethnic origin. So far, more than 6000 healthy volunteers have been evaluated, making this one of the largest population pharmacogenomic studies worldwide. Three symposia were organized, 'Pharmacogenetics of indigenous and mestizos populations and its clinical implications', 'Methodological innovation in pharmacogenetics and its application in health', and 'General discussion and concluding remarks', about mechanisms and proposals for training, diffusion of pharmacogenetics for Spanish- and Portuguese-speaking health professionals, and 'bench to bedside' pilot projects.

Prenatal diagnosis of L1 cell adhesion molecule mutations. Capabilities and limitations.

OBJECTIVE: Discuss the capability for and limitations of prenatal detection of L1 cell adhesion molecule (L1CAM) mutations. METHODS: Haplotype analysis by PCR and PAGE. Mutation detection by SSCP, followed by dideoxy sequencing. Confirmation of sequencing results with PCR and NcoI digestion. RESULTS: A 1-bp deletion was found in exon 2 of L1CAM in all affected males and obligate carriers in the pedigree. Prenatal detection is now possible for subsequent pregnancies. CONCLUSION: In a large gene with widespread mutations such as L1CAM, a mutation must be detected in another family member before direct prenatal mutation testing can be done within the required timeframe. If the proper family members are available, haplotyping offers a fast but indirect test with several limitations.