title: Distribution of polymorphisms in the CYP2C9 gene and CYP2C19/CYP2C9 haplotypes among Venezuelan populations.
abstract: BACKGROUND
  Polymorphisms with decreased enzyme activity of their gene products have been reported in region CYP2C with population variations in haplotype structure.
  
  
  OBJECTIVE
  To estimate the allelic and genotypic frequencies of variants CYP2C9*2 and CYP2C9*3 and of CYP2C9/CYP2C19 haplotypes in Venezuelan populations.
  
  
  METHODS
  Six hundred and thirty-four individuals from nine admixed populations (AP) and the Warao indigenous group were studied. Allelic frequencies, linkage disequilibrium and genetic distances for haplotypes were calculated and compared within Venezuela and with data available in the literature.
  
  
  RESULTS
  Heterogeneity in the distribution of CYP2C9 alleles and CYP2C9/CYP2C19 haplotypes among the AP and the Warao was observed. The joint frequency of haplotypes, with at least one non-functional variant, shows values in AP between 21-41%, while in Warao it reaches 5%. The haplotype that includes the Asian and rare Latin America CYP2C19*3 allele was detected in most AP and in Warao. Pairwise Fst values showed that the Warao was an outlier compared with the AP, while these are closer to European-derived populations. No significant correlation was found between haplotype frequencies and admixture.
  
  
  CONCLUSIONS
  These results support the need to understand the distribution of genomic biomarkers related to the metabolism of drugs, for planning national public health strategies.
authors.affiliation: a Laboratorio de Genética Humana, Centro de Medicina Experimental , Instituto Venezolano de Investigaciones Científicas , Caracas , Venezuela.
authors.forename: Sara
authors.initials: S
authors.lastname: Flores-Gutiérrez
authors.affiliation: a Laboratorio de Genética Humana, Centro de Medicina Experimental , Instituto Venezolano de Investigaciones Científicas , Caracas , Venezuela.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Rodríguez-Larralde
authors.affiliation: b Departamento de Bioanálisis , Universidad de Oriente (UDO) , Cumaná , Venezuela.
authors.forename: Merlyn
authors.initials: M
authors.lastname: Vívenes de Lugo
authors.affiliation: a Laboratorio de Genética Humana, Centro de Medicina Experimental , Instituto Venezolano de Investigaciones Científicas , Caracas , Venezuela.
authors.forename: Dinorah
authors.initials: D
authors.lastname: Castro de Guerra
mesh_terms: D065731:Cytochrome P-450 CYP2C19 / Q000235:genetics*; D065729:Cytochrome P-450 CYP2C9 / Q000235:genetics*; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D007199:Indians, South American / Q000235:genetics; D015810:Linkage Disequilibrium; D011110:Polymorphism, Genetic; D014687:Venezuela; D044465:White People / Q000235:genetics
chemical_list: C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19
keywords: CYP2C19/CYP2C9 haplotypes; Venezuela; rs1057910; rs1799853