Sickle Cell Disease in a Patient with Sickle Cell Trait and Compound Heterozygosity for Hemoglobin S and Hemoglobin Quebec–Chori

THE sickle cell trait is generally considered to be benign, because the presence of hemoglobin A in a concentration of more than 50 percent in the red cells of persons heterozygotic for hemoglobin A and hemoglobin S (hemoglobin A/S) prevents the polymerization of the remaining hemoglobin S under physiologic conditions. 1 Occasional reports suggest, however, that after extreme physical stress or hypoxia, the sickle cell trait can be associated with serious morbidity and even death. 2 – 4 In most cases, the diagnosis of this trait is straightforward: hematologic measures such as hemoglobin, hematocrit, red-cell indexes, and the reticulocyte count are normal, and electrophoretic . . .