Background: Elevated fibrinogen levels have been linked to increased risk for deep venous thrombosis, although it is not clear whether fibrinogen is causal or rather a marker for the presence of other risk factors. A common G/A polymorphism in the gene for the fibrinogen beta-chain (FGB G-455A) is associated with elevated fibrinogen levels. The present study was designed to analyze the role of this genetic marker for deep venous thrombosis.
Materials and methods: We performed a case-control study including 307 patients with documented deep venous thrombosis and 316 control subjects. beta-fibrinogen genotypes were determined by allele-specific polymerase chain reaction.
Results: GG, GA and AA genotype frequencies were similar among the patients (53.1%, 41.0, 5.9) and controls (51.6%, 42.1, 6.3; P = 0.92). Fibrinogen levels of the patients (median 3.72 g l-1; range 1.93-11.6) did not differ significantly from those of the controls (3.76; 2.17-9.99). Carriers of the homozygous AA genotype had significantly higher fibrinogen levels than noncarriers (patients: 5.32 vs. 3.59; P = 0.024; controls: 6.29 vs. 3.72; P = 0.048).
Conclusion: Our data suggest that the fibrinogen-elevating FGB G-455A gene polymorphism is not linked to an increased risk for deep venous thrombosis.