DNA polymorphism patterns in the beta-globin gene cluster in the Japanese population.

Restriction site polymorphisms in the beta-globin gene cluster on chromosome #11 were analyzed in healthy Japanese. The beta A chromosomes were mapped by scoring the presence (+) or the absence (-) of seven different restriction sites (Hinc II site 5' to the epsilon-globin gene; Hind III sites in the G gamma- and A gamma-globin genes; Hinc II sites in and 3' to the psi beta 1-globin gene; Ava II site in the beta-globin gene; Bam HI site 3' to the beta-globin gene). No chromosomes with [- +] for two Hind III sites in the G gamma- and A gamma-globin genes, or those with [+ -] for two Hinc II sites in and 3' to the psi beta 1-globin gene, were observed. It was observed that homozygosity for the presence of the Hinc II site 5' to the epsilon-globin gene (+/+) always accompanied the homozygosity for the absence of the Hinc II sites in and 3' to the psi beta 1-globin gene (--/--). Almost all A gamma T chromosomes possessed a subhaplotype [- + + - +] 5' to the beta-globin gene. More than half of the beta A chromosomes observed in the Japanese showed haplotype VII, which may be characteristic for Asians. It was deduced that frameworks 1, 2, and 3 of the beta-globin gene in the Japanese comprised 16%, 18%, and 66%, respectively.