hereditary persistence of fetal hemoglobin

hereditary persistence of fetal hemoglobin

Hbα₂γ₂ An AD condition caused by a defect in the Hb 'switch' mechanism, where the usual transition from γ to β chain production does not occur; in HPFH, the number of cells with Hb F in the maternal circulation is greater than the baby's total blood volume, and therefore the condition's presence is suspected by mere calculations of maternal and fetal volumes; Type I–uniform distribution of HbF in all RBCs, as in Greek, Kenyan and Black American forms 2. Type II–heterogeneous distribution of HbF in RBCs, as in British and Swiss forms. See Class switching, Fetal hemoglobin.