A minor hemoglobin (Hb) component with the electrophoretic properties of the δ-chain variant Hb A2′ was encountered in two unrelated families of Russian-Jewish ancestry. This minor component, designated Hb NYU, was shown to result from the substitution of lysine for asparagine at δ12. We have confirmed studies of others that hemoglobin A2′ isolated from the hemoglobin of some African subjects, results from the replacement of the normal glycine at δ16 by arginine. Thus for interpretations of the incidence of δ-chain variants in different populations, electrophoretic data are not sufficient.
Helen M. Ranney, Alan S. Jacobs, Bracha Ramot, Thomas B. Bradley Jr.