FV Leiden, FII G20210A and MTHFR C677T mutations in patients with lower or upper limb deep vein thrombosis

Deep vein thrombosis (DVT) is a multifactorial disease that occurs with frequency of 1/1000 per year. The FV Leiden, FII G20210A and MTHFR C677T mutations represent genetic factors for the occurrence of vein thrombosis. The goal of this study was to determine the frequency of these mutations in patients with DVT of upper and lower limbs. The study encompassed 119 patients divided in two groups. The group of patients with the lower limbs thrombosis included 77 patients, while the upper limbs thrombosis group included 42 patients. The presence of FV Leiden, FII G20210A and MTHFR C677T mutations was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. In patients with DVT of lower limbs, the frequency of FV Leiden mutation was 26,0% in heterozygous form and 1,3% in homozygous form. In the group of patients with DVT of upper limbs, the frequency of heterozygous carriers was 7.2%. In patients with DVT of lower limbs, FII G20210A mutation occurred in heterozygous form in 15.6% subjects, and in the group with DVT of upper limbs the frequency was 7.2% in heterozygous and 2.3% in homozygous form. The frequency of MTHFR C677T mutation in patients with lower limbs DVT was 42.8% in heterozygous form and 13% in homozygous form, while in the group of patients with upper limbs DVT, the frequency was 52.4% in heterozygous form and 9.5% in homozygous form. The FV Leiden and FII G20210A mutations represent significant risk factors for the occurrence of DVT of lower limbs. These mutations are less frequent in DVT of upper limbs and more extensive further studies are needed to determine their potential role. The MTHFR C677T mutation represents less significant risk factor for lower limb DVT and should be taken into account only in cases when it occurs in combination with other risk factors