The protective effect of FXIII Val34Leu polymorphism against deep vein thrombosis: a report from Iranian Blood Transfusion Organization (IBTO)

Background: The coagulation factor XIII is a pro-transglutaminase enzyme with tetrameric structure. An exchange of G for A in exon 2 of A subunit results in replacement of valine with leucine in amino acid 34. As a result of this substitution mutation, the clots produced are fragile and loose therefore it seems that FXIII Val34Leu polymorphism acts as a factor for individual protection against thrombosis Objectives: To determine the prevalence and role of FXIIIA Val34Leu polymorphism against deep vein thrombosis. Methods: This was a retrospective case-control study performed on 116 patients with DVT who were referred to Thrombosis and Homeostasis Laboratory affiliated to Iranian Blood Transfusion Organization. Also, 100 healthy individuals (blood donors) were recruited as control. Following DNA extraction and application of PCR and RFLP techniques in presence of restriction enzyme Cfo1, the genotypes of FXIII Val34Leu polymorphism were identified. The data were analyzed using chi square test as well as calculation of OD ratio and 95% confidence interval. Findings: The prevalence of FXIII Val34Leu polymorphism among the case and control groups was 22.4% and 37.4%, respectively. While the allele frequency of leucine in case group was 14.7% it was 20.2 % in control group. No significant correlation between polymorphism and sex was established. Conclusion: According to our data, no association between the FXIII Val34Leu polymorphism and protection against deep vein thrombosis was demonstrated. Therefore, it seems that this polymorphism occurs as a natural phenomenon and unaffected by gender.