Hemoglobin Volga, β27 (B9) Ala→Asp: Functional and Clinical Correlations of an Unstable Hemoglobin

Hb Volga (β27 Ala→Asp) on the basis of physical tests is only a mildly unstable hemoglobin yet it is associated with a gross re-ticulocytosis. This is partly explicable by an increased oxygen affinity with a compensating erythrocytosis but there is also brisk hemolysis. It is not certain that this hemolysis is due to precipitation of the hemoglobin as in vitro inclusion body formation is not remarkable and there is no evidence of preferential proteolysis of the abnormal subunits, at least in the reticulocytes. There is increased autoxidation and it may be the consequence of this that is the prime cause of hemolysis.