Hemoglobin Barcelona beta 94 (FG1) Asp leads to His : a new hemoglobin Variant with increased oxygen affinity

A new variant, Hb Barcelona (beta 94 Asp leads to His) found in a Spanish family presenting with a mild polycythemia, is described. Its increase in oxygen affinity is explained by the rupture of the salt-bridge between beta 94 Asp and beta 146 His which normally stabilizes the deoxystructure and accounts for approximately half of the Bohr effect. A comparison between the estimated oxygen transport to the tissues by the blood from a patient with Hb Kempsey and that of the patients with Hb Barcelona showed, in the latter cases, that an almost normal oxygen delivery was obtained by the increase of the hemoglobin level.