β-Thalassemia in the American Negro

Abstract

A C T In Italian patients with high hemoglobin A2 fl-thalassemia trait, the synthesis of P-chains of adult hemoglobin in the peripheral blood is approximately one-half that of a-chains. In this study the relative rates of f-and a-chain synthesis were determined in 26 Negro heterozygotes and five homozygotes for fi-thalassemia in six families. The 8/a ratio of globin synthesis was decreased in only 15 heterozygotes, whereas in the other 11, fl/a globin synthesis was in the normal range or was slightly increased. These unusual findings did not appear to be due to the presence of a-thalassemia or a hyperactive "normal" fl-allele. This study demonstrates that the f8/a ratio of globin synthesis in the peripheral blood is normal in some patients with P-thalassemia trait. In five Negro homozygotes with relatively mild clinical disease the f/a ratios were similar to those of Caucasians with Cooley's anemia. Further studies are needed to explore the relationship between normal synthesis ratios in many Negro heterozygotes and milder clinical disease in homozygotes in the same families.