Hemoglobin S-O Arab-alpha-thalassemia: globin biosynthesis and clinical picture.

A 22 year old American negro with mild anemia was found to be triply heterozygous for hemoglobin S, hemoglobin O Arab and alpha thalassemia. Hemoglobin A was not detected in the subject's hemolysate. The alpha thalassemia gene was expressed by an alpha/non-alpha synthesis ratio of 0.71 plus or minus 0.07 and was equally rates unbalanced in the peripheral blood and the bone marrow. The total radioactivity of the abnormal chains was equal, indicating equal rates of transcription and translation of the abnormal structural genes. Since the rate of synthesis of betaS and betaO was equal to the proportions of these abnormal chains in the peripheral blood, the abnormal gene products were equally stable. The mildness of the anemia, compared to that of the other reported S-O Arab double heterozygotes, may be due to the moderating influene of the alpha thal gene.