Hemostatic parameters in Brazilian asymptomatic carriers of Factor V Leiden, prothrombin (G20210A) and methylenetetrahydrofolate reductase (C677T) mutations

Abstract number: P0371

Godoi L. C., Carvalho M. G., Fernandes A. P. S. M., Vieira L. M., Giumarães D. A. M., Lages G. F. G., Bragança W. F., Souza R. C. C., Abrão R. C. O., Dusse L. M. S.

UFMG, Brazil

Thrombophilia is defined as a tendency to develop thrombosis as a consequence of predisposing factors that may be genetically determined and/or aquired, resulting in hypercoagulable states. Numerous studies have linked the presence of the factor V Leiden (G1691A), prothrombin (G20210A) and/or methylenetetrahydrofolate reductase (C677T – MTHFR) mutations to thrombophilia due to the high incidence of these mutations among patients who developed thrombotic episodes, especially younger patients. However, the laboratory investigation of hypercoagulable states is very recent. The main objective of this study was to investigate the hemostatic status of younger carriers of at least one of the aforementioned mutations and asymptomatic for thrombosis. Polimerase chain reaction and restriction fragment length polymorphism/PCR-RFLP were used for mutation analysis and the hemostatic status of 64 carriers, from 11 families, and 18 normal subjects (controls), with no acquired risk factors, was evaluated by thrombomodulin (TM), prothrombin fragment 1 + 2 (F1 + 2), thrombin-anti-thrombin complex (TAT), D-Dimer (D-d) and fibrin products plasma levels (degradation) determination. Homo or heterozygous MTHFR mutation was detected FDP in all the families studied. The mutations for factor V Leiden and in the prothrombin gene were present in nine and four families, respectively. Four families had at least two of these mutations. The hemostatic status in these asymptomatic carriers did not vary significantly when compared to the mean values obtained for control subjects, considering any of the studied markers. Based on these results, we concluded that the presence of factor V Leiden, protrombin or MTHFR mutations, isolated or in combination, seems not to predispose younger carriers, with no acquired risk factors, to a hypercoagulable state.