Slovenský hematolologický portál - The factor V R2 allele: risk of venous thromboembolism

The factor V R2 allele: risk of venous thromboembolism, factor V levels and resistance to activated protein C.
Luddington R, Jackson A, Pannerselvam S, Brown K, Baglin T.

Department of Haematology, Addenbrooke's NHS Trust, Cambridge, United Kingdom.

Thrombosis and haemostasis, 2000 Feb;83(2):204-8.

Case-control studies have yielded conflicting results regarding the relative risk of venous thromboembolism associated with the factor V R2 allele. We calculated odds ratios in 581 patients and 469 age-matched controls. The odds ratio for the R2 allele in patients relative to controls was 1.21 (95% CI 0.84 to 1.74). These results do not support the hypothesis that the R2 allele is a risk factor for venous thromboembolism. There was no relationship between factor V levels and R2 carrier status. Normalised APC sensitivity ratios were not lower in carriers of the R2 allele. In an in vitro model progressive APC resistance was observed with factor V levels of 60% and less but ratios less than 2.4 (equivalent to a normalised ratio of 0.73) did not occur until factor V levels were less than 20%. The relationship between APC resistance and factor V level was not observed in a factor VIII-independent model.