title: The influence of ethnicity on warfarin dosage requirements in the chilean population.
abstract: BACKGROUND
  Vitamin K antagonists are drugs that are widely prescribed around the world and their use has helped improve the prognosis of patients with thromboembolic disease. However, a high interindividual variability has been observed in dosage requirements to reach the desired anticoagulation range that could be due to environmental and genetic factors. Studies suggest that ethnicity influences coumarin response, supporting the observed differences in dose requirements across various populations. Studies using mitochondrial DNA (mtDNA) markers have suggested that the Chilean population has a predominantly Amerindian genetic pool.
  
  
  OBJECTIVE
  To evaluate the influence of ethnicity, defined by the presence of Amerindian mtDNA haplogroups, on the variability in therapeutic response to warfarin in the Chilean population.
  
  
  METHODS
  A total of 191 patients treated with warfarin were included in this study. Analysis of the mitochondrial genome for detecting the presence of Amerindian mtDNA haplogroups was performed using polymerase chain reaction and polymerase chain reaction restriction fragment length polymorphism techniques. The evaluation of warfarin requirements according to each haplogroup was performed by ANOVA with a 95% CI and assuming statistical significance at P < 0.05.
  
  
  RESULTS
  Based on the presence of an mtDNA haplogroup, 91% of the Chilean population had an Amerindian background. There were no significant differences in warfarin dosage requirements among the different Amerindian haplogroups (P = 0.083).
  
  
  CONCLUSIONS
  The presence of Amerindian mtDNA haplogroup does not influence warfarin dosage requirements in the Chilean population.
authors.affiliation: The Clinical and Immunohematological Department, Faculty of Health Sciences, Universidad de Talca, Talca, Chile ; Molecular Diagnosis Laboratory, Faculty of Health Sciences, Universidad San Sebastián, Concepcion, Chile.
authors.forename: Valeska
authors.initials: V
authors.lastname: Subiabre
authors.affiliation: The Clinical and Immunohematological Department, Faculty of Health Sciences, Universidad de Talca, Talca, Chile.
authors.forename: Ivan
authors.initials: I
authors.lastname: Palomo
authors.affiliation: Molecular Diagnosis Laboratory, Faculty of Health Sciences, Universidad San Sebastián, Concepcion, Chile ; Escuela de Ciencias de la Salud, Universidad Católica de Temuco, Temuco, Chile.
authors.forename: Neftalí
authors.initials: N
authors.lastname: Guzmán
authors.affiliation: Biomedical Laboratory Department, The National Hematology Reference Laboratory, Chile's Public Health Institute, Santiago, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Retamales
authors.affiliation: Escuela de Tecnología Médica. Universidad Mayor, Santiago, Chile.
authors.forename: Hugo
authors.initials: H
authors.lastname: Henríquez
authors.affiliation: Internal Medicine Department, Universidad de La Frontera, Temuco, Chile.
authors.forename: Luis
authors.initials: L
authors.lastname: Gonzalez
keywords: anticoagulant therapy; mitochondrial DNA; pharmacogenomics; warfarin