Factor V Leiden, MTHFR C677T and Prothrombin Gene Mutation G20210A in Iranian Patients with Venous Thrombosis

Background: Factor V Leiden, Prothrombin gene (G20210A) and MTHFR (C677T) polymorphism are the main biomarkers for evaluation of tendency for venous thromboembolism. We aimed to investigate the frequency of mutations in factor V Leiden, Prothrombin G20210A and MTHFR C677T and identify the genetic status for these mutations in patients with venous thrombosis. Methods: This study was carried out in 312 patients with venous thrombosis who were referred to “Thrombosis Clinical center”, Imam Khomeini Hospital, Tehran, Iran and “Sarvar Clinic”, Mashhad, Iran. Identification of gene mutations was performed using PCR-restriction fragment length polymorphism (RFLP)- based method. Results: The prevalence of Factor V Leiden mutation was 35.8%, while 8.9% of them were homozygous for AA allele and 26.9% had the GA allele in heterozygous state. The prevalence of MTHFR (C677T) mutation was 17.9% of which 7.1% had the TT mutant allele in homozygous and 10.8% had CT allele in heterozygous state. The prevalence of mutation in prothrombin gene G20210A was 8.9% with all cases heterozygous for GA mutant allele. Conclusion: In our study from two referral centers for thrombotic disorders, the prevalence of mutations in gene encoding factor V Leiden was higher than Prothrombin 20210A and MTHFR C677T polymorphisms. Therefore, assay for factor V Leiden mutation has the first priority in the evaluation of patients with hereditary thrombophilia in these geographical regions.