Thrombotic Risk Evaluation of Two Methylenetetrahydrofolate Reductase Mutations C677t and A1298c in Venous Thromboembolism

The MTHFR mutations C677T and A1298C combined with folate and vitamin B12 deficiency lead to hypercoagulability. We evaluated thrombotic risk due to MTHFR mutations, individually and in combination, in patients with venous thromboembolism (VTE). The case-control study included groups of 262 VTE patients and 101 healthy controls. Allelic distribution of MTHFR C677T/A1298C mutations was determined by real-time polymerase chain reaction and results were statistically analyzed using χ2-test and comparison of proportions with 95% confidence intervals (95% CI) and p=0.05. There was no statistically significant difference in the frequencies of C677T MTHFR genotypes between the patient group and controls (p=0.676; odds ratio (OR)=1.297; 95% CI 0.649- 2.592), or for A1298C mutation (p=0.872; OR=0.894; 95% CI 0.564-1.419). The allele distribution of both MTHFR mutations did not show any significant differences (C677T p=0.808; OR=1.043; 95% CI 0.741-1.468 and A1298C p=0.738; OR=0.943; 95% CI 0.667-1.332). MTHFR genotype distributions did not show any significant difference between genders when analyzed with χ2-test. When evaluating a combination of mutations, the greatest difference between the cases and controls was found in the frequencies of MTHFR TT/AA carriers (2.6%), which, however, did not reach significance (p=0.520). In conclusion, MTHFR C677T and A1298C mutations do not represent risk factors for VTE development in the group of Croatian patients.