Arg506Gln mutation of the coagulation factor V gene not detected in Japanese pulmonary thromboembolism

Summary The incidence of pulmonary thromboembolism (PTE) is lower in Japanese than in Caucasians. The basis for the different incidence has not been clarified. A poor anticoagulant response to activated protein C based on a single point mutation of the factor V gene (Arg506Gln) was found to be a pathogenetic factor for venous thrombosis and PTE in North America and Europe. We investigated whether the Arg506Gln mutation of factor V is responsible for the occurrence of PTE among Japanese. We analyzed genomic DNA prepared from fresh peripheral blood of 25 patients with PTE of unknown etiology (12 of acute type and 13 of chronic type) and that of 110 controls without respiratory or circulatory disorders. To detect the Arg506Gln mutation, 267bp DNA fragments of the factor V gene including the Arg506Gln region were amplified by PCR, digested byMnlI and electrophoresed. After digestion of PCR products withMnlI, DNA fragments of 163bp length, but not DNA fragments of 200bp length, were identified in all samples, indicating the absence of the Arg506Gln mutation in the patients with PTE and control subjects. These results suggest that the Arg506Gln mutation is absent or very rare and not an important pathogenetic factor for PTE in Japanese.