Homozygotes for the hereditary persistence of fetal hemoglobin: the ratio of G gamma to A gamma chains and biosynthetic studies.

Two sons of a previously reported Ghanaian homozygote for the hereditary persistence of fetal hemoglobin (HPFH) (Ringelhann et al., 1970) also are HPFH homozygotes. In addition, another unrelated adult Ghanaian homozygote has been detected. All of these Ghanaian homozygotes as well as three American Black HPFH homozygotes have the G gamma A gamma type of HPFH with a G gamma to A gamma ratio of about 3:2, in contrast to an Asiatic Indian homozygote who has the G gamma type. Globin chain synthesis in HPFH homozygotes is unbalanced, with a gamma/alpha ratio of 0.6 or less, whereas it is balanced in heterozygotes according to most reports.