Common origin of the I1307K APC polymorphism in Ashkenazi and non-Ashkenazi Jews

A common germline missense mutation within the APC gene, I1307K, has recent ly been described in Ashkenazi Jews. We detected this polymorphism in two n on-Ashkenazi Jewish women using denaturing gradient gel electrophoresis (DG GE), and hypothesized that in Jewish individuals it might not be restricted to Ashkenazim, and actually reflect a common ancestral polymorphism. To te st this notion we performed allelic pattern determination using APC-linked markers in these two women and in nine Ashkenazi carrier controls, The patt ern of the intragenic markers, as well as a single downstream marker 30-70 Kb from the APC gene was identical in all individuals, regardless of ethnic origin. We conclude that the I1307K polymorphism in Jewish individuals, is not restricted to Ashkenazim and probably reflects a founder mutation.