Hemoglobin Malmö Beta-97 (FG-4) histidine--glutamine: a cause of polycythemia.

A striking history of familial polycythemia led to a search for an abnormal hemoglobin. None could be demonstrated by routine electrophoretic methods, but the propositus' hemolysate had increased oxygen affinity. Manipulation of the conditions of electrophoresis, and chromatographic methods, permitted identification of hemoglobin Malmö. Studies of hemolysates demonstrated a normal Bohr effect, decreased heme-heme interaction (n=1.58), and a p50 of 1.3 mm Hg at 10 degrees C and pH 7.2. The amino acid substitution occurs in the same position (FG-4) as that of hemoglobin Chesapeake, but in the beta-chain rather than the alpha-chain. The two types of hemolysate have different pathophysiologic properties, and carriers of hemoglobin Malmö exhibit more striking hematologic abnormalities.