INCREASED HBF IN SICKLE-CELL-ANEMIA IS DETERMINED BY A FACTOR LINKED TO THE BETA-S GENE FROM ONE PARENT

Abstract

Members of 7 large families, containing 20 patients with sickle cell anemia (SS) characterized by high levels of HbF, were studied using immunofluorescence to count F cells and a radioimmunoassay to measure small amounts of HbF. In 5 of these families, 1 of the sickle cell trait (AS) parents had a much higher HbF and F-cell count than the other; in 1 family, both parents had a marked increase in HbF and F cells; in the remaining family, HbF and F cells were at borderline values in both parents. Seven of 14 AS siblings, but only 1 of 8 normal Hb (AA) siblings, also had HbF and F-cell counts above the normal range. A factor for increased F cells, linked to the .beta.s gene of 1 parent, apparently is segregating in these families and is responsible for the greatly increased HbF and F cells in the SS subjects. HbF/F cell in AS parents and siblings was the same as that of normal AA subjects, whereas in the SS offspring it was greatly increased, suggesting that it was the result of marrow hyperplasia associated with their hemolytic anemia. The similarity of this increased F-cell gene to heterocellular hereditary persistence of HbF (HPFH), Swiss type, is discussed; it may control the persistent synthesis of HbF in sickle cell anemia by its presence in early infancy.