Haemoglobin Radcliffe (α2β299(G1)Ala): A High Oxygen‐Affinity Variant Causing Familial Polycythaemia

Abstract
Three members of an Oxfordshire family have polycythacmia. In each case their whole‐blood oxygen affinity is increased. This is due to a previously undescribed haemoglobin variant which has been named haemoglobin Radcliffe (α2β299(G1)Ala). In addition to having a high oxygen affinity haemoglobin Radcliffe shows virtually no haem‐haem interaction and a diminished Bohr effect. It is synthesized at the same rate and is as stable as haemoglobin A. X‐ray analysis indicates that crystals of deoxyhaemoglobin Radcliffe are isomorphous with those of deoxyhaemoglobin A. Solutions of haemoglobin Radcliffe were also studied by high‐resolution proton nuclear magnetic resonance spectroscopy. The structure/function relationships of haemoglobin Radcliffe are discussed in the light of these studies.