Hemoglobin Fannin-Lubbock [α₂β₂119(GH2) Gly → Asp]. A New Hemoglobin Variant at the α₁β₁ Contact

Hemoglobin Fannin-Lubbock was found in a 9-year-old Mexican-American female. The abnormal hemoglobin was detected as a fast-moving variant by electrophoresis on cellulose acetate at pH 8.4. Structural analysis indicated a substitution in the β-chain of aspartic acid for glycine at position 119, a position involved in the α₁β₁ contact of the hemoglobin tetramer. This contact between unlike chains is larger and undergoes a smaller shift during the process of oxygenation and deoxygenation than the α₁β₂ contact (Perutz, M.F., Muirhead, H., Cox, J.M. and Goaman L.C.G. (1968) Nature 219, 131-139). Mutations in this contact tend to cause slight or no changes in functional behavior. Apart from a mild anemia, the propositus did not exhibit any obvious clinical symptoms.