Characterization of Abnormalities in the γ-Globin Gene Arrangements of Japanese Newborns

Abstract

Cord blood samples from 889 healthy Japanese newborns from three districts of Honshu Island were studied with the purpose of characterizing the γ-globin genes in the Japanese. The A_γT gene frequency was 0.159 which is the same as that found elsewhere in Japan. The haplotype of the chromosome with the found elsewhere A_γT gene was [-+ + - + (+ or -) (+ or -)] at eight polymorphic sites. Data from analyses of DNA and the proportion of γ chains in Hb F showed the existence of various kinds of γ-globin gene arrangements; six genotypes were observed for individuals with high G_γ values and triple or quadruple γ-globin gene arrangements, and seven genotypes for babies with low G_γ values and a single γ-globin gene. The in vivo expression of the γ-globin gene located at the third or fourth position in the multiple gene arrangement was found to be about 5% and 2.5% of the total, respectively. The haplotype for the chromosomes with a triple γ-globin gene was [+ — (-) — +], but that for the chromosomes with a single γ-globin gene remains unclear. In addition, a new type of Bgl II polymorphism in the G_γ-globin gene was observed.