Globin Chain Synthesis in HbD ( Punjab ) - 6 - Tha 1 assemia

A 23-yr-old man of Greek-Italian ancestry with mild anemia was found to be heterozygousforHbD(Punjab) fi12 glu -‘ gIn and fi-thalassemia. HbA was not detected upon electrophoresis of the subject’s hemolysate, and no synthesis of fiA globin was demonstrated after incubation of peripheral blood or bone marrow with 3H-Ieucine. The thalassemia gene was thus of the fi variety. The fiD/a synthesis ratios were almost equally unbalanced in the blood and bone marrow: 0.53 and 0.61, respectively. The mother of the propositus had fi-thalassemia trait. In peripheral blood the fiA/a synthesis ratio was 0.38. The mutant /3#{176} gene thus appeared potentially capable of directing the synthesis of globin chains as efficiently as a normal fi gene. The mildness of the HbD-fi-thalassemia syndrome appeared to be due to the maintenance of a relatively high total fl/a synthesis ratio in the presence of a physiologically neutral structural mutation.