Fetal hemoglobin variants in 80,000 Japanese neonates: high prevalence of Hb F Yamaguchi (A gamma T 80 Asp----Asn).

A population-based screening of newborns for the structural variants of fetal hemoglobin was carried out in Osaka Prefecture, Japan, by isoelectric focusing of globin chains using dried blood on filter paper. Of 80,000 newborns, 18 had alpha globin variants and 55 had gamma globin variants. The incidence of gamma globin variants (1/1,455) was much higher than that of alpha globin variants (1/4,444). Structural studies were then carried out on the abnormal gamma globins in 36 samples, and revealed that 25 of them were Hb F Yamaguchi (A gamma T 80 Asp----Asn). The prevalence of this variant in Japanese was estimated to be as high as one per 2,100.