title: Risk of recurrent venous thrombosis in patients with G20210A mutation in the prothrombin gene or factor V Leiden mutation.
abstract: The impact of the G20210A prothrombin mutation, factor V Leiden and 677T mutation of methylene tetrahydrofalate reductase (MTHFR) in recurrent deep venous thrombosis (DVT) is not so clear. We have prospectively monitored 259 patients following a first episode of DVT in order to determine which factors influence the development of a recurrent event. Several clinical and biological factors together with the genetic polymorphisms of factor V Leiden, G20210A prothrombin and 677T MTHFR were assessed. During a median follow-up of 786 patient-years, 27 patients (14%) developed one objective episode of recurrent venous thrombosis. The carriers of a double defect, homozygous or double heterozygous for factor V Leiden and G20210A, had an increased risk after a first episode of DVT, while patients who were isolated heterozygous for factor V Leiden or G20210 had a risk of recurrent DVT similar to patients who had neither mutation (annual incidence of 12.1, 3.1, 2.9 and 2.8%). The 677T MTHFR mutation alone or combined with hyperhomocysteinemia was not associated with an increased risk of recurrent events. The development of proximal DVT (P=0.01) and the presence of a double defect (P=0.01) were the only two risk factors independently associated with a high recurrence ratio in the multivariate analysis. Thus, the annual incidence of DVT recurrence in patients without any of these two risk factors was only 0.6% (95% confidence interval, 0.2-0.9). We have identified a group of patients with DVT but at very low risk of re-thrombosis in whom an extended secondary thromboprophylaxis should be carefully considered.
authors.affiliation: Department of Hematology, University Hospital of Salamanca, Spain. gonzapor@hotmail.com
authors.forename: José Ramón
authors.initials: JR
authors.lastname: González-Porras
authors.forename: Ramón
authors.initials: R
authors.lastname: García-Sanz
authors.forename: Ignacio
authors.initials: I
authors.lastname: Alberca
authors.forename: María Luz
authors.initials: ML
authors.lastname: López
authors.forename: Ana
authors.initials: A
authors.lastname: Balanzategui
authors.forename: Oliver
authors.initials: O
authors.lastname: Gutierrez
authors.forename: Francisco
authors.initials: F
authors.lastname: Lozano
authors.forename: Jesús
authors.initials: J
authors.lastname: San Miguel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002675:Child, Preschool; D004812:Epidemiologic Methods; D005165:Factor V / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D017354:Point Mutation; D011516:Prothrombin / Q000235:genetics*; D012008:Recurrence; D020246:Venous Thrombosis / Q000188:drug therapy / Q000235:genetics*
chemical_list: C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D042965:Methylenetetrahydrofolate Reductase (NADPH2)