Hemoglobin-Seattle (α2Aβ276Glu): An Unstable Hemoglobin Causing Chronic Hemolytic Anemia

Mild to moderate chronic hemolytic anemia in a mother and her two sons was found to be associated with the presence of about 40 per cent abnormal hemoglobin of rapid electrophoretic mobility: Hb-Seattle. Hb-Seattle was found to be unstable in vitro. It was shown to be due to a replacement of alanine by glutamic acid at position 76 of the ft hemoglobin chain. The substitution occurs at the surface of the ft hemoglobin chain. The hemoglobin instability was attributed to an abnormal interaction between the substituted glutamic acid and histidine at position ft11.