Abstract
Three members of a family who have erythrocytosis and a new hemoglobin, designated hemoglobin Yakima, are described. The abnormal hemoglobin is characterized by the substitution of histidine for aspartic acid at residue 99 in the beta-chain. Of three possible structure-function relations which would account for the increased oxygen affinity of hemoglobin Yakima, only two seem likely. These are: (a) an intrachain shift in the normal relations between the F and G helices and the heme group, or (b) an effect of the substituted side chain at a region of contact between nonpolar residues of the alpha- and beta-chains which favors the oxyhemoglobin quarternary structure.