Genetic regulation of gamma gene expression: study of the interaction of beta-thalassemia with heterocellular HPFH.

A family has been observed which a gene for heterocellular hereditary persistence of fetal hemoglobin (HPFH), probably identical to that previously described as Swiss type HPFH, has been inherited together with beta-thalassemia. The interaction of these two genes resulted in beta-thalassemia heterozygotes with unusually high levels of fetal hemoglobin (3.6-6.