If besides hemoglobin SS patients also have hemoglobin F (HbF) in their erythrocytes, it reduces the degree of aggregation and crystallization of hemoglobin S, and as a result, they tend to have fewer symptoms of sickle cell anemia or lack them completely. When the HbF levels increase polymerization of deoxy sickle hemoglobin slows down. HbF decreases HbS concentration, and together with its mixed hybrid tetramer (?2?S?) are not able to enter the deoxy sickle hemoglobin polymer phase. The antipolymerization effect of HbF resides primarily in HBG (both ?-globin genes) residues glycine ?87 and aspartic acid ?80. By inhibiting the tendency of deoxy sickle hemoglobin to polymerize, sufficient HbF thwarts the cellular damage evoked by HbS polymer
Copyright 2019 - Education WordPress Theme.