A single genetic origin for a common Caucasian risk factor for venous thrombosis.

A common genetic risk factor for venous thrombosis among Caucasoid subpopulations is a polymorphism, nt G1691A, in blood coagulation factor V that replaces Arg506 with Gln and imparts resistance of factor Va to the anticoagulant, activated protein C. Haplotype analyses using six dimorphic sites in the factor V gene for 117 Caucasian subjects of Jewish, Arab, Austrian, and French origin who were homozygous for nt A1691 compared with 167 controls (nt G1691) support a single origin for this polymorphism. The nt G1691A mutation is estimated to have arisen circa 21,000 to 34,000 years ago, ie, after the evolutionary divergence of Africans from non-Africans and of Caucasoid from Mongoloid subpopulations.