Hemoglobin Columbia Missouri or alpha 2[88 (F9) Ala----Val]beta 2: a new high-oxygen-affinity hemoglobin that causes erythrocytosis.

Abstract

A previously undescribed hemoglobin variant, hemoglobin Columbia Missouri, alpha 88 (F9) Ala----Val, was detected in a 22-year-old white man who was undergoing assessment for erythrocytosis. This new hemoglobin variant does not separate from hemoglobin A by electrophoresis in conventional media, by isoelectric focusing, or by electrophoresis of purified globin chains in 8 M urea. It exhibits a high oxygen affinity, with a P50 (oxygen tension at 50% saturation) of 19.3 torr for the patient's whole blood. The substitution of hemoglobin Columbia Missouri is an internal residue near the end of the F helix of the alpha chain. Hemoglobin Okazaki has an arginyl residue substitution for a cysteinyl residue at F9 (beta 93) in the beta chain. In comparison with hemoglobin Okazaki, the substitution in hemoglobin Columbia Missouri has a more pronounced effect on oxygen affinity. Consequently, hemoglobin Columbia Missouri is associated with erythrocytosis, whereas hemoglobin Okazaki is not.