VKORC1 gene polymorphism (-1639G>A) in warfarin therapy patients of Pakistani population

Objective: To observe vitamin K epoxide reductase complex subunit 1-1639 G>A polymorphism in patients resistant to warfarin therapy, and to calculate the allele frequency of the polymorphism in local patients. Method: The cross-sectional case-control study was conducted at the Punjab Institute of Cardiology, Lahore, from 2013 to 2014 and comprised patients with heart valve replacement. Thy were divided into warfarin-resistant group 1 taking 10mg/day, 70mg/week and control group 2 taking a standard dose of 5mg/day, 35mg/week. The vitamin K epoxide reductase complex subunit 1-1639 G>A polymorphism analysis was done by polymerase chain reaction, followed by restriction fragment length polymorphism technique. Data was analysed using SPSS 20. Results: Of the 146 patients, there were 73(50%) in each of the two groups. In group 1, there were 37(50.68%) males and 36(49.32%) were females with an overall mean age of 33 +/- 12 years, while group 2 had 36(49.32%) males and 37(50.68%) females with an overall mean age of 37 +/- 13 years. There were no significant differences in mean values of age, serum cholesterol, triglycerides and albumin levels between the groups (p>0.05). The G allele was the most frequently found in both groups, with 140(96%) in group-1 and 137(94%) in group-2. Overall, the homozygous GG genotype was significantly higher in the sample 132(90.4%) (p<0.05). Conclusions: There was evidence found that vitamin K epoxide reductase complex subunit 1-1639 G>A polymorphism alone not be the dominant genetic factor associated with warfarin response variability.

Automated summary

This study aimed to observe the vitamin K epoxide reductase complex subunit 1-1639 G>A polymorphism in patients resistant to warfarin therapy and determine its allele frequency in the local population. The results showed that this polymorphism alone is not the dominant genetic factor associated with warfarin response variability.