Idiopathic Heinz Body Anaemia: Hb‐Bristol (β67 (E11) Val→Asp)

Summary. It is shown that the haemolytic anaemia in the original patient with ‘idiopathic Heinz body anaemia’ is due to the presence of 36% unstable haemoglobin: Hb‐Bristol (β67 (E11) Val→Asp). This haemoglobin has a low oxygen affinity which accounts for the normal development of this patient in spite of the presence of permanent severe anaemia. The relative rates of synthesis of βBristol‐ to βA‐chains were identical, indicating that the reduced amount of Hb‐Bristol found in the haemolysate is due to precipitation of the abnormal protein. The inability to separate this haemoglobin by electrophoresis is due to interaction of the abnormal aspartic acid with the adjacent histidine at β63 (E7).