Benign sickle cell anemia in Israeli-Arabs with high red cell 2,3 diphosphoglycerate

Arabs living near the Sea of Galilee were found to be homozygous for hemoglobin S. Studies of solubility, mechanical precipitability, electrophoretic mobility on starch-gel and citrate agar media, minimum gelling concentration, and peptide mapping of the hemoglobin beta-chain confirmed complete identity of the hemoglobin with that found in Afro-American hemoglobin S homozygotes. A comparison of Arab Hb S homozygotes with Afro-American Hb S patients showed no significant differences in hemoglobin levels, red cell indices or morphology. Hb F averaged 4.4% in Arab patients. The 2,3 diphosphoglycerate levels were increased approximately twofold in Arabs, whereas in Afro-Americans, it was increased by only 7% in females and 20% in males.