title: Influence of CYP4F2 genotype on warfarin dose requirement-a systematic review and meta-analysis.
abstract: BACKGROUND
  Warfarin is a commonly used oral anticoagulant and the dosage is individually adjusted on the basis of the international normalized ratio (INR) monitoring. It is well known that gene polymorphisms of CytochromeP450 (CYP) 2C9 gene and the vitamin K epoxide reductase complex 1 (VKORC1) were significantly associated with warfarin dose. However, the association between Cytochrome P450 4F2 (CYP4F2) polymorphism and warfarin dose requirement is still controversial. This study was to investigate the influence of the CYP4F2 polymorphism, V433M (rs2108622) on warfarin dose for patients by meta-analysis.
  
  
  METHODS
  Strict inclusion and exclusion criteria were set, and the studies prior to December 19, 2010 were searched in PubMed, EMBASE and CNKI. References were examined and experts of primary studies were consulted for additional information. Revman 5.0.2 software was used to analyze the relationship between warfarin maintenance dose and CYP4F2 polymorphism
  
  
  RESULTS
  Thirteen studies were included in the meta-analysis which consisted of Caucasian, Asian and African populations. Compared to individuals with the homozygous CYP4F2 genotype (CC), carriers of CT, TT genotypes required 10.0% (95% confidence interval(CI) 4.0-15.0) and 21.0% (95% CI 9.0-33.0) higher warfarin doses respectively (P value <0.05). In addition, T carriers required 11.0% (95% CI 6.0-17.0) higher warfarin dose than CC genotype.
  
  
  CONCLUSIONS
  Our study showed that polymorphism of CYP4F2 had a moderate but statistically significant association with the variation of interindividual warfarin dose. However, whether CYP4F2 can improve the prediction of warfarin dose warrants need further investigation when combined with environmental factors.
authors.affiliation: Heart Center, Peking University People's Hospital, Beijing, China.
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Liang
authors.forename: Chunling
authors.initials: C
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Dayi
authors.initials: D
authors.lastname: Hu
authors.forename: Yihong
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000483:Alleles; D000925:Anticoagulants / Q000008:administration & dosage*; D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D000072470:Cytochrome P450 Family 4; D054796:Drug Dosage Calculations; D005838:Genotype; D006470:Hemorrhage / Q000209:etiology / Q000235:genetics; D006801:Humans; D011110:Polymorphism, Genetic; D012307:Risk Factors; D014859:Warfarin / Q000008:administration & dosage*; D044465:White People / Q000235:genetics
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D003577:Cytochrome P-450 Enzyme System; D000072470:Cytochrome P450 Family 4; C117480:CYP4F2 protein, human