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Carvalho VHV, Rodrigues JCG, Vinagre LWMS, Pereira EEB, Monte N, Fernandes MR, Ribeiro-Dos-Santos AM, Guerreiro JF, Ribeiro-Dos-Santos Â, Dos Santos SEB, Dos Santos NPC. Genomic investigation on genes related to mercury metabolism in Amazonian indigenous populations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171232. [PMID: 38402986 DOI: 10.1016/j.scitotenv.2024.171232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Studies have identified elevated levels of mercury in Amazonian Indigenous individuals, highlighting them as one of the most exposed to risks. In the unique context of the Brazilian Indigenous population, it is crucial to identify genetic variants with clinical significance to better understand vulnerability to mercury and its adverse effects. Currently, there is a lack of research on the broader genomic profile of Indigenous people, particularly those from the Amazon region, concerning mercury contamination. Therefore, the aim of this study was to assess the genomic profile related to the processes of mercury absorption, distribution, metabolism, and excretion in 64 Indigenous individuals from the Brazilian Amazon. We aimed to determine whether these individuals exhibit a higher susceptibility to mercury exposure. Our study identified three high-impact variants (GSTA1 rs1051775, GSTM1 rs1183423000, and rs1241704212), with the latter two showing a higher frequency in the study population compared to global populations. Additionally, we discovered seven new variants with modifier impact and a genomic profile different from the worldwide populations. These genetic variants may predispose the study population to more harmful mercury exposure compared to global populations. As the first study to analyze broader genomics of mercury metabolism pathways in Brazilian Amazonian Amerindians, we emphasize that our research aims to contribute to public policies by utilizing genomic investigation as a method to identify populations with a heightened susceptibility to mercury exposure.
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Affiliation(s)
- Victor Hugo Valente Carvalho
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil.
| | - Juliana Carla Gomes Rodrigues
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - Lui Wallacy Morikawa Souza Vinagre
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - Esdras Edgar Batista Pereira
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - Natasha Monte
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - Marianne Rodrigues Fernandes
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - André Maurício Ribeiro-Dos-Santos
- Laboratório de Genética Humana e Médica, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Pará, Brazil
| | - João Farias Guerreiro
- Laboratório de Genética Humana e Médica, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Pará, Brazil
| | - Ândrea Ribeiro-Dos-Santos
- Laboratório de Genética Humana e Médica, Instituto de Ciências Biológicas, Universidade Federal do Pará, 66075-110, Belém, Pará, Brazil
| | - Sidney Emanuel Batista Dos Santos
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
| | - Ney Pereira Carneiro Dos Santos
- Núecleo de Pesquisas em Oncologia, Unidade de Alta Complexidade em Oncologia, Hospital Universitário João de Barros Barreto, 66073-005 Belém, Pará, Brazil
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Perini JA, Basta PC, Suarez-Kurtz G. NUDT15 and TPMT polymorphisms in three distinct native populations of the Brazilian Amazon. Front Pharmacol 2024; 15:1359570. [PMID: 38379902 PMCID: PMC10876798 DOI: 10.3389/fphar.2024.1359570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/18/2024] [Indexed: 02/22/2024] Open
Abstract
This is the first report of the distribution of TPMT and NUDT15 single nucleotide polymorphisms and metabolic phenotypes associated with cytotoxicity of thiopurine drugs, in indigenous groups of Brazilian Amazon: Munduruku, Paiter-Suruí and Yanomami. The minor allele frequency (MAF) of NUDT15 rs116855232 did not differ significantly across the groups; TPMT rs1800462 was absent, while rs1800460 and rs1142345 were in strong linkage disequilibrium, and 10- and 30-fold more common in Paiter-Suruí. Indeed, the MAFs in Paiter-Surui (0.193 and 0.188) are the largest report globally. The distribution of combined NUDT15/TPMT metabolic phenotypes differed significantly (p < 0.0001) and largely (Cramér´s V = 0.37) across cohorts. This has important pharmacogenetic implications: the Clinical Pharmacogenetics Implementation Consortium recommendations to reduce or consider reduction of thiopurine dose applies to 4.4% Yanomami, 5.6% Munduruku, versus 41% Paiter-Suruí. The proportion of Paiter-Suruí at risk of thiopurine intolerance is 3- to 4-fold higher than any other population worldwide.
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Affiliation(s)
- Jamila Alessandra Perini
- Laboratório de Pesquisa de Ciências Farmacêuticas (LAPESF), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, Brazil
| | - Paulo Cesar Basta
- Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz (ENSP/Fiocruz), Rio de Janeiro, Brazil
| | - Guilherme Suarez-Kurtz
- Divisão de Pesquisa Clínica e Desenvolvimento Tecnológico, Coordenação de Pesquisa, Instituto Nacional de Câncer, Rio de Janeiro, Brazil
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Basta PC, Viana PVDS, de Vasconcellos ACS, Périssé ARS, Hofer CB, Paiva NS, Kempton JW, Ciampi de Andrade D, de Oliveira RAA, Achatz RW, Perini JA, Meneses HDNDM, Hallwass G, Lima MDO, de Jesus IM, dos Santos CCR, Hacon SDS. Mercury Exposure in Munduruku Indigenous Communities from Brazilian Amazon: Methodological Background and an Overview of the Principal Results. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:9222. [PMID: 34501811 PMCID: PMC8430525 DOI: 10.3390/ijerph18179222] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 12/20/2022]
Abstract
The Amazonian indigenous peoples depend on natural resources to live, but human activities' growing impacts threaten their health and livelihoods. Our objectives were to present the principal results of an integrated and multidisciplinary analysis of the health parameters and assess the mercury (Hg) exposure levels in indigenous populations in the Brazilian Amazon. We carried out a cross-sectional study based on a census of three Munduruku indigenous villages (Sawré Muybu, Poxo Muybu, and Sawré Aboy), located in the Sawré Muybu Indigenous Land, between 29 October and 9 November 2019. The investigation included: (i) sociodemographic characterization of the participants; (ii) health assessment; (iii) genetic polymorphism analysis; (iv) hair mercury determination; and (v) fish mercury determination. We used the logistic regression model with conditional Prevalence Ratio (PR), with the respective 95% confidence intervals (CI95%) to explore factors associated with mercury exposure levels ≥6.0 µg/g. A total of 200 participants were interviewed. Mercury levels (197 hair samples) ranged from 1.4 to 23.9 μg/g, with significant differences between the villages (Kruskal-Wallis test: 19.9; p-value < 0.001). On average, the general prevalence of Hg exposure ≥ 6.0 µg/g was 57.9%. For participants ≥12 years old, the Hg exposure ≥6.0 µg/g showed associated with no regular income (PR: 1.3; CI95%: 1.0-1.8), high blood pressure (PR: 1.6; CI95%: 1.3-2.1) and was more prominent in Sawré Aboy village (PR: 1.8; CI95%: 1.3-2.3). For women of childbearing age, the Hg exposure ≥6.0 µg/g was associated with high blood pressure (PR: 1.9; CI95%: 1.2-2.3), with pregnancy (PR: 1.5; CI95%: 1.0-2.1) and was more prominent among residents in Poxo Muybu (PR: 1.9; CI95%: 1.0-3.4) and Sawré Aboy (PR: 2.5; CI95%: 1.4-4.4) villages. Our findings suggest that chronic mercury exposure causes harmful effects to the studied indigenous communities, especially considering vulnerable groups of the population, such as women of childbearing age. Lastly, we propose to stop the illegal mining in these areas and develop a risk management plan that aims to ensure the health, livelihoods, and human rights of the indigenous people from Amazon Basin.
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Affiliation(s)
- Paulo Cesar Basta
- Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz (ENSP/Fiocruz), Rua Leopoldo Bulhões, 1480-Manguinhos, Rio de Janeiro 21041-210, Brazil; (A.R.S.P.); (S.d.S.H.)
| | - Paulo Victor de Sousa Viana
- Centro de Referência Professor Hélio Fraga, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz (CRPHF/ENSP/Fiocruz), Estrada de Curicica, 2000-Curicica, Rio de Janeiro 22780-195, Brazil;
| | - Ana Claudia Santiago de Vasconcellos
- Laboratório de Educação Profissional em Vigilância em Saúde, Escola Politécnica de Saúde Joaquim Venâncio, Fundação Oswaldo Cruz (EPSJV/Fiocruz), Av. Brazil, 4365-Manguinhos, Rio de Janeiro 21040-900, Brazil;
| | - André Reynaldo Santos Périssé
- Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz (ENSP/Fiocruz), Rua Leopoldo Bulhões, 1480-Manguinhos, Rio de Janeiro 21041-210, Brazil; (A.R.S.P.); (S.d.S.H.)
| | - Cristina Barroso Hofer
- Instituto de Pediatria e Puericultura Martagão Gesteira, Faculdade de Medicina, Universidade Federal do Rio de Janeiro (UFRJ), Rua Bruno Lobo, 50-Cidade Universitária, Rio de Janeiro 21941-912, Brazil;
| | - Natalia Santana Paiva
- Instituto de Estudos em Saúde Coletiva (IESC), Universidade Federal do Rio de Janeiro (UFRJ), Avenida Horácio Macedo, s/n, Ilha do Fundão-Cidade Universitária, Rio de Janeiro 21941-598, Brazil;
| | - Joseph William Kempton
- Faculty of Medicine, Imperial College London, Medical School Building, St Mary’s Hospital, Norfolk Place, London W2 1PG, UK;
| | - Daniel Ciampi de Andrade
- Centro de Dor, Departamento de Neurologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), Av. Dr. Enéas Carvalho de Aguiar, 255-Cerqueira César, São Paulo 05403-000, Brazil; (D.C.d.A.); (R.A.A.d.O.)
| | - Rogério Adas Ayres de Oliveira
- Centro de Dor, Departamento de Neurologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), Av. Dr. Enéas Carvalho de Aguiar, 255-Cerqueira César, São Paulo 05403-000, Brazil; (D.C.d.A.); (R.A.A.d.O.)
| | - Rafaela Waddington Achatz
- Programa de Pós-Graduação em Psicologia Clínica do Instituto de Psicologia da Universidade de São Paulo (USP), Av. Professor Mello Moraes, 1721-Butantã, São Paulo 05508-030, Brazil;
| | - Jamila Alessandra Perini
- Laboratório de Pesquisa de Ciências Farmacêuticas (LAPESF), Centro Universitário Estadual da Zona Oeste (UEZO), Av. Manuel Caldeira de Alvarenga, 1.203, Rio de Janeiro 23070-200, Brazil;
| | - Heloísa do Nascimento de Moura Meneses
- Programa de Pós-Graduação em Ciências da Saúde (PPGCSA), Universidade Federal do Oeste do Pará, Rua Vera Paz Av. Vera Paz, s/n, Bairro Salé, 1° Pavimento, Bloco Modular Tapajós, Unidade Tapajós, Santarém, Pará 68035-110, Brazil;
| | - Gustavo Hallwass
- Programa de Pós-Graduação em Biociências (PPGBio), Universidade Federal do Oeste do Pará, Rua Vera Paz, s/n, Bairro Salé, Santarém 68035-110, Brazil;
| | - Marcelo de Oliveira Lima
- Seção de Meio Ambiente, Instituto Evandro Chagas, Secretaria de Vigilância em Saúde, Ministério da Saúde (SEAMB/IEC/SVS/MS), Rodovia BR-316 km 7, s/n, Levilândia 67030-000, Brazil; (M.d.O.L.); (I.M.d.J.)
| | - Iracina Maura de Jesus
- Seção de Meio Ambiente, Instituto Evandro Chagas, Secretaria de Vigilância em Saúde, Ministério da Saúde (SEAMB/IEC/SVS/MS), Rodovia BR-316 km 7, s/n, Levilândia 67030-000, Brazil; (M.d.O.L.); (I.M.d.J.)
| | - Cleidiane Carvalho Ribeiro dos Santos
- Distrito Sanitário Especial Indígena Rio Tapajós (DSEI), Secretaria Especial de Saúde Indígena Tapajós (Sesai), Av. Santa Catarina, 10° Rua, nº 96, Bairro Bela Vista, Itaituba 68180-210, Brazil;
| | - Sandra de Souza Hacon
- Departamento de Endemias Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz (ENSP/Fiocruz), Rua Leopoldo Bulhões, 1480-Manguinhos, Rio de Janeiro 21041-210, Brazil; (A.R.S.P.); (S.d.S.H.)
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Duconge J, Ruaño G. Preventing the exacerbation of health disparities by iatrogenic pharmacogenomic applications: lessons from warfarin. Pharmacogenomics 2018; 19:875-881. [PMID: 29898627 DOI: 10.2217/pgs-2018-0055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Jorge Duconge
- Pharmaceutical Sciences Department, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, PO Box 365067, San Juan, PR 00936, USA
| | - Gualberto Ruaño
- Institute of Living at Hartford Hospital, Hartford, CT 06102, USA
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Suarez-Kurtz G, Paula DP, Struchiner CJ. Pharmacogenomic implications of population admixture: Brazil as a model case. Pharmacogenomics 2014; 15:209-19. [DOI: 10.2217/pgs.13.238] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The heterogeneous Brazilian population, with European, African and Amerindian ancestral roots is a model case for exploring the impact of population admixture on the frequency distribution of polymorphisms in pharmacogenes, and the design and interpretation of pharmacogenomics trials. Examples drawn from studies carried out by researchers of the Brazilian pharmacogenomics network, support the following conclusions: the distribution of polymorphisms varies across geographical regions and self-reported ‘race/color’ categories, and is best modeled as continuous functions of individual proportions of European and African ancestry; the differential frequency of polymorphisms impacts the calculations of sample sizes required for adequate statistical power in clinical trials performed in different segments of the Brazilian population; and extrapolation of pharmacogenomics data from well-defined ethnic groups to Brazilians is plagued with uncertainty. Data for warfarin and tacrolimus are reviewed to highlight the advantages and challenges of performing pharmacogenomic trials in Brazilians.
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Affiliation(s)
- Guilherme Suarez-Kurtz
- Programa de Farmacologia, Instituto Nacional do Câncer, Rio de Janeiro, RJ, 20231-050, Brazil
| | - Daniela Polessa Paula
- Departamento de Matemática, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil
| | - Claudio J Struchiner
- Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, 21040-360, Brazil
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Fung E, Patsopoulos NA, Belknap SM, O'Rourke DJ, Robb JF, Anderson JL, Shworak NW, Moore JH. Effect of genetic variants, especially CYP2C9 and VKORC1, on the pharmacology of warfarin. Semin Thromb Hemost 2012; 38:893-904. [PMID: 23041981 DOI: 10.1055/s-0032-1328891] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The genes encoding the cytochrome P450 2C9 enzyme (CYP2C9) and vitamin K-epoxide reductase complex unit 1 (VKORC1) are major determinants of anticoagulant response to warfarin. Together with patient demographics and clinical information, they account for approximately one-half of the warfarin dose variance in individuals of European descent. Recent prospective and randomized controlled trial data support pharmacogenetic guidance with their use in warfarin dose initiation and titration. Benefits from pharmacogenetics-guided warfarin dosing have been reported to extend beyond the period of initial dosing, with supportive data indicating benefits to at least 3 months. The genetic effects of VKORC1 and CYP2C9 in African and Asian populations are concordant with those in individuals of European ancestry; however, frequency distribution of allelic variants can vary considerably between major populations. Future randomized controlled trials in multiethnic settings using population-specific dosing algorithms will allow us to further ascertain the generalizability and cost-effectiveness of pharmacogenetics-guided warfarin therapy. Additional genome-wide association studies may help us to improve and refine dosing algorithms and potentially identify novel biological pathways.
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Affiliation(s)
- Erik Fung
- Section of Cardiology, Heart & Vascular Center, Lebanon, New Hampshire 03756, USA.
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Valentin II, Vazquez J, Rivera-Miranda G, Seip RL, Velez M, Kocherla M, Bogaard K, Cruz-Gonzalez I, Cadilla CL, Renta JY, Feliu JF, Ramos AS, Alejandro-Cowan Y, Gorowski K, Ruaño G, Duconge J. Prediction of warfarin dose reductions in Puerto Rican patients, based on combinatorial CYP2C9 and VKORC1 genotypes. Ann Pharmacother 2012; 46:208-18. [PMID: 22274142 DOI: 10.1345/aph.1q190] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The influence of CYP2C9 and VKORC1 polymorphisms on warfarin dose has been investigated in white, Asian, and African American populations but not in Puerto Rican Hispanic patients. OBJECTIVE To test the associations between genotypes, international normalized ratio (INR) measurements, and warfarin dosing and gauge the impact of these polymorphisms on warfarin dose, using a published algorithm. METHODS A retrospective warfarin pharmacogenetic association study in 106 Puerto Rican patients was performed. DNA samples from patients were assayed for 12 variants in both CYP2C9 and VKORC1 loci by HILOmet PhyzioType assay. Demographic and clinical nongenetic data were retrospectively collected from medical records. Allele and genotype frequencies were determined and Hardy-Weinberg equilibrium (HWE) was tested. RESULTS Sixty-nine percent of patients were carriers of at least one polymorphism in either the CYP2C9 or the VKORC1 gene. Double, triple, and quadruple carriers accounted for 22%, 5%, and 1%, respectively. No significant departure from HWE was found. Among patients with a given CYP2C9 genotype, warfarin dose requirements declined from GG to AA haplotypes; whereas, within each VKORC1 haplotype, the dose decreased as the number of CYP2C9 variants increased. The presence of these loss-of-function alleles was associated with more out-of-range INR measurements (OR = 1.38) but not with significant INR >4 during the initiation phase. Analyses based on a published pharmacogenetic algorithm predicted dose reductions of up to 4.9 mg/day in carriers and provided better dose prediction in an extreme subgroup of highly sensitive patients, but also suggested the need to improve predictability by developing a customized model for use in Puerto Rican patients. CONCLUSIONS This study laid important groundwork for supporting a prospective pharmacogenetic trial in Puerto Ricans to detect the benefits of incorporating relevant genomic information into a customized DNA-guided warfarin dosing algorithm.
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Affiliation(s)
- Isa Ivette Valentin
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Puerto Rico, San Juan, Puerto Rico
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Vargens DD, Damasceno A, Petzl-Erler ML, Suarez-Kurtz G. Combined CYP2C9, VKORC1 and CYP4F2 frequencies among Amerindians, Mozambicans and Brazilians. Pharmacogenomics 2011; 12:769-72. [PMID: 21692610 DOI: 10.2217/pgs.11.35] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Vargens DD, Petzl-Erler ML, Suarez-Kurtz G. Distribution of CYP2C Polymorphisms in an Amerindian Population of Brazil. Basic Clin Pharmacol Toxicol 2011; 110:396-400. [DOI: 10.1111/j.1742-7843.2011.00807.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Suarez-Kurtz G. Pharmacogenetics in the brazilian population. Front Pharmacol 2010; 1:118. [PMID: 21833165 PMCID: PMC3153000 DOI: 10.3389/fphar.2010.00118] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 08/27/2010] [Indexed: 12/23/2022] Open
Abstract
Brazil is the fifth largest country in the world and its present population, in excess of 190;million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans, and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians: most individuals, irrespective of self-identification as White, Brown or Black - the major categories of the Brazilian Census "race/color" system - have significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx) implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g., CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc) varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV protease inhibitors and non-steroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first-generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen, a nation-wide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact.
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Affiliation(s)
- Guilherme Suarez-Kurtz
- Divisão de Farmacologia, Coordenação de Pesquisa, Instituto Nacional de CâncerRio de Janeiro, Brazil
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Orsi FA, Annichino Bizzacchi JM, de Paula EV, Ozelo MC, Langley MR, Weck KE. VKORC1 V66M mutation in African Brazilian patients resistant to oral anticoagulant therapy. Thromb Res 2010; 126:e206-10. [PMID: 20615525 DOI: 10.1016/j.thromres.2010.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 05/12/2010] [Accepted: 06/07/2010] [Indexed: 11/28/2022]
Abstract
Warfarin-based anticoagulant therapy is associated with large variability in dose response. Genetic variability in the VKORC1 and CYP2C9 genes is associated with increased warfarin sensitivity. In addition, rare coding region mutations in VKORC1 have been associated with resistance to warfarin. VKORC1 and CYP2C9 variability associated with altered warfarin response is less well characterized in African and mixed-raced populations such as Brazilians. To determine genetic variability associated with altered warfarin response among Brazilian patients, sixty-two adult patients with extreme resistance or sensitivity to warfarin were genotyped for variants in CYP2C9 and VKORC1. Of the 51 patients on low doses of warfarin, the VKORC1--1639 (3673) G>A polymorphism associated with warfarin sensitivity was present in 48 (94.1%), including 97% of Caucasians, 82% of African-descent patients, and all 7 (100%) patients of Indian descent. Additionally, 52.9% of warfarin sensitive patients had at least one CYP2C9*2 or CYP2C9*3 decreased metabolism allele, 63.6% of Caucasians and 54% of African-descent patients. Of the 11 patients on high doses of warfarin, sequencing of VKORC1 revealed a nonsynonymous V66M mutation in two warfarin resistant patients, both of African-descent. Brazilian patients requiring low doses of warfarin have a high frequency of VKORC1 and CYP2C9 variants associated with warfarin sensitivity. The presence of the rare VKORC1 V66M in two warfarin high dose outlier patients implies that this variant may be more frequent among African Brazilians and has implications for future warfarin studies in other populations of African descent.
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Affiliation(s)
- Fernanda A Orsi
- Hematology and Hemotherapy Center, State University of Campinas, Brazil.
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Villagra D, Duconge J, Windemuth A, Cadilla CL, Kocherla M, Gorowski K, Bogaard K, Renta JY, Cruz IA, Mirabal S, Seip RL, Ruaño G. CYP2C9 and VKORC1 genotypes in Puerto Ricans: A case for admixture-matching in clinical pharmacogenetic studies. Clin Chim Acta 2010; 411:1306-11. [PMID: 20488169 DOI: 10.1016/j.cca.2010.05.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 05/07/2010] [Accepted: 05/10/2010] [Indexed: 01/29/2023]
Abstract
BACKGROUNDS Admixture is of great relevance to the clinical application of pharmacogenetics and personalized medicine, but unfortunately these studies have been scarce in Puerto Ricans. Besides, allele frequencies for clinically relevant genetic markers in warfarin response (i.e., CYP2C9 and VKORC1) have not yet been fully characterized in this population. Accordingly, this study is aimed at investigating whether a correlation between overall genetic similarity and CYP2C9 and/or VKORC1 genotypes could be established. METHODS 98 DNA samples from Puerto Ricans were genotyped for major CYP2C9 and VKORC1 polymorphisms and tested on a physiogenomic (PG)-array to infer population structure and admixture pattern. RESULTS Analysis affirmed that Puerto Ricans are broadly admixed. A genetic distance dendrogram was constructed by clustering those subjects with similar genetic profiles. Individual VKORC1 and CYP2C9 genotypes were visually overlaid atop the three dendrogram sectors. Sector-1, representing Amerindian ancestry, showed higher VKORC1 -1639G>A variant frequency than the rest of the population (p=0.051). Although CYP2C9*3 allele frequencies matched the expected HapMap values, admixture may explain deviations from published findings regarding VKORC1 -1639G>A and CYP2C9*2 allele frequencies in sector-3. CONCLUSIONS Results suggest that the observed inter-individual variations in ancestral contributions have significant implications for the way each Puerto Rican responds to warfarin therapy. Our findings provide valuable evidence on the importance of controlling for admixture in pharmacogenetic studies of Puerto Rican Hispanics.
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Affiliation(s)
- David Villagra
- Laboratory of Personalized Health, Genomas, Inc., Hartford, CT 06106, USA
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Lee MTM, Chen CH, Chuang HP, Lu LS, Chou CH, Chen YT, Liu CY, Wen MS, Lu JJ, Chang CF, Wu JY, Chen YT. VKORC1 haplotypes in five East-Asian populations and Indians. Pharmacogenomics 2010; 10:1609-16. [PMID: 19842934 DOI: 10.2217/pgs.09.80] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
AIMS Warfarin, a widely prescribed oral anticoagulant, is used for the prevention of thromboembolism. Several polymorphisms in VKORC1 have been shown to be associated with warfarin dose requirements. The frequencies of these VKORC1 polymorphisms display population differences; however, this has not been examined in many populations. In this study, we examined VKORC1 polymorphisms in five East-Asian populations (Han Chinese, Indonesian, Filipino, Thai and Vietnamese) and Indians. MATERIALS & METHODS A total of six SNPs in the VKORC1 gene (-1639G>A, 497T>G, 1173C>T, 1542T>G, 2255C>T and 3730G>A) were genotyped. Frequencies, linkage disequilibrium and haplotype structures of these six VKORC1 SNPs were analyzed. RESULTS Our data showed that 497T>G is only polymorphic in the Indian population. The 497G allele is very rare in the East-Asian populations (frequency < 1%). The remaining SNPs demonstrated high linkage disequilibrium and had similar frequencies and haplotype structures in all but the Indian population. The Indian population is mostly made up of the H7 haplotype (76%) while the rest of the recruited populations consisted of the H1 haplotype (> 80%).
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Affiliation(s)
- Ming Ta Michael Lee
- Institute of Biomedical Sciences, Academia Sinica, 128 Academia Road, Section 2, NanKang, Taipei, Taiwan
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