HEMOGLOBIN-S-thalassemia disease (microdrepanocytic disease) is the result of double heterozygosity for the genes of hemoglobin S and thalassemia. Its highest incidence would be expected where areas of high density of thalassemia and sicklemia are geographically proximal. Sicily and southern Italy are such places, and recently Silvestroni and Bianco * have reported 57 cases in 28 families from there. In this country only 22 cases have been reported,† most of them in patients of Sicilian, Italian, or Greek ancestry. Indeed, most of the cases of sickle-cell anemia reported in white persons, in retrospect, were probably examples of S-thalassemia, and Chernoff15 in his excellent review estimates that there are at least 14 of these in the literature. Since thalassemia minor is known to occur also in the Negro,16 and we have seen six such cases, S-thalassemia would be expected to be found in this race. There are five reports ‡ of