Population genetics of factor V Leiden in Europe.

We have analyzed 5971 control individuals originating from 26 geographically defined populations in Europe and neighboring countries for the presence of factor V Leiden, an important genetic risk factor in venous thromboembolism. The mean frequency of the mutation in the populations studied is 0.027%, with a peak value incidence of more than 12% in Cyprus; the mutation is absent in Inuits and is at low incidence in French Basques. A west to east increasing cline of allele factor V Leiden prevalence (r = 0.479, p < 0.02) was observed in Europe, together with a decreasing south to north cline (r = -0.801, p < 0.001) of these values-but in this last situation only when southwest populations are excluded from the analysis. Based on these findings, an interpretation is proposed of the history of factor V Leiden expansion in Europe during the Neolithic period, from a probable Anatolian center of origin in Turkey. Copyright 2001 Academic Press.