Liang R et al. – The 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.

• 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.

• 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.