title: ABO blood group but not haemostasis genetic polymorphisms significantly influence thrombotic risk: a study of 180 homozygotes for the Factor V Leiden mutation.
abstract: Limited data exist on the impact of additional genetic risk factors on the clinical manifestations of factor (F) V Leiden homozygotes. A retrospective multi-centre cohort study was performed to assess the role of the FII G20210A gene mutation, the protein C (PC) promoter CG haplotype, the combination of two PC polymorphisms (A-1641G, C-1654T), the FXIII Val34Leu polymorphism, two thrombin-activatable fibrinolysis inhibitor polymorphisms (Thr325Ile, Ala147Thr), two plasminogen activator inhibitor-1 polymorphisms (-675 4G/5G, A-844G), the methylene-tetrahydrofolate reductase (MTHFR) C677T polymorphism and the ABO blood group on the thrombotic phenotype in FV Leiden homozygotes. 127 subjects with venous thrombosis and 53 asymptomatic subjects were analysed. The T allele of MTHFR C677T was more frequent in symptomatic subjects than in asymptomatic ones (68% vs. 45%, P = 0.02; odds ratio (OR) 2.8, 95% CI 1.3-5.8, after adjustment for potential confounders). For the other polymorphisms, no difference was observed between symptomatic and asymptomatic subjects. The non-O blood group was more frequent among symptomatic carriers (84% vs. 57%, P = 0.0002; OR 4.1, 95% CI 1.7-9.7). In conclusion, except for the ABO blood group, none of the polymorphisms studied contribute strongly to the thrombotic risk in FV Leiden homozygotes.
mesh_terms: D000017:ABO Blood-Group System; D000328:Adult; D016022:Case-Control Studies; D005165:Factor V / Q000235:genetics*; D005176:Factor XIII / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006487:Hemostasis / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D016015:Logistic Models; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D011486:Protein C / Q000235:genetics; D011516:Prothrombin / Q000235:genetics; D012189:Retrospective Studies; D012306:Risk; D020246:Venous Thrombosis / Q000097:blood / Q000235:genetics*
chemical_list: D000017:ABO Blood-Group System; D017395:Plasminogen Activator Inhibitor 1; D011486:Protein C; C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D005176:Factor XIII; D042965:Methylenetetrahydrofolate Reductase (NADPH2)