The venous thrombosis risk factor 20210 A allele of the prothrombin gene is not a major risk factor for arterial thrombotic disease.

A nucleotide change (G to A transition) at position 20210 has recently been demonstrated to be a risk factor for venous thrombosis. The relevance of this polymorphism to thrombotic disease was investigated by genotypic identification in three prospective case-control studies: 101 case patients with acute coronary heart disease (CHD), 104 patients with acute cerebrovascular disease (CVD), 82 patients with a confirmed diagnosis of deep venous thrombosis (DVT), and one control age- and sex-matched for each patient. The prevalence of the genetic variation was significantly associated with the occurrence of DVT, but did not differ in patients with CHD or CVD from that in controls, suggesting that this allele should not be considered a major risk factor for arterial thrombotic disease.