Elevated ^Gγ Gene Expression with Specific β^s Gene Haplotype, Normal γ Gene Maps and Presence of the Xmn I site -158 5′ to the ^Gγ Gene in Indian Sickle Cell Anemia

Abstract

In nine Indian patients ranging in age between four and 61 years, with mild Hb SS disease and very high Hb F levels, the ^Gγ globin chain levels of their fetal hemoglobin ranged between 64.0% and 70.0%, with a mean of 68.1% (S.D. ± 2.6) of the total amount of γ-globin chains. Eight of the nine patients were homozygous for a specific β^s gene haplotype #31. The other one was doubly heterozygous for the same specific haplotype and another haplotype, which differed from haplotype #31 by the presence of Bam HI site 3' to the β gene and absence of Pvu II site 5' to the ψβ gene. The β gene organization studied by Pst I restriction enzyme analysis was found to be normal and the Xmn I site -158 5' to ^GYβ gene was present in all patients examined.