• αThalassemia is common in southeast Asia and the Mediterranean, where the predominant lesion seems to be a deletion of one or more of the four gene loci responsible for αglobin chain production. In the United States, the prevalence of αthalassemia in blacks was once thought to be low, but more recent studies show that the prevalence of αthalassemia is high. We measured the globin chain synthetic ratios in 144 black Americans to determine the prevalence and hematologic manifestations of αthalassemia in this population. There were 120 subjects with a mean synthetic ratio of 0.986 ± 0.04, with a range of 0.90 to 1.06; these were classified as normal. Five subjects were found to have βthalassemia; 19 subjects had mild α-thalassemia. The overall gene frequency for α-thalassemia was estimated to be 0.07 in this population. The hemoglobin values of subjects with mild α-thalassemia were not statistically significantly different from normal black or white control subjects of the same sex, but there was a significant decrease in the mean corpuscular volume and in the mean corpuscular hemoglobin value.
(Arch Intern Med 1982;142:1280-1282)