PERCENT-HB A2, PERCENT-HB-F, PERCENT-G-GAMMA VALUES AND THE HAPLOTYPES IN THE BETA-GLOBIN GENE-CLUSTER IN JAPANESE ADULTS WITH ELEVATED HB-F

The percentages of minor adult hemoglobin (% Hb A2) in hemolysates and (G)gamma-globin chain (% (G)gamma) in fetal Hb (Hb F) of 15 individuals with elevated Hb F levels (2.0-11%) among 11,000 healthy Japanese adults were examined. Most of them might be carriers for the determinants of hereditary persistence of fetal hemoglobin. Subjects with less than 1.3% Hb A2, some of whom might be also carriers for delta-thalassemia determinants, had high (G)gamma values (54-70%). Those homozygous for a subhaplotype [+-----] 5' to the delta-globin gene had low to mid (G)gamma values (7-49%), while those homozygous for [-++-++] possessed high (G)gamma values (60-85%), but varied Hb F values (3.1-11%). Those heterozygous for the presence of the XmnI site 5' to (-158 bp to the cap site of) the (G)gamma-globin gene had mid to high (G)gamma values (53-65%). Factors for the high or low (G)gamma-globin gene expression in the Japanese adult with elevated Hb F level should be highly associated with a subhaplotype [-++-++] or [+-----], respectively.