BRIEF REPORT: Absence of Hemoglobin A in a Double Heterozygote for F-Thalassemia and Hemoglobin S

An adult with minor hematologic abnormalities and hemoglobin electrophoretic pattern characterized by large amounts of hemoglobins S and F together with absent hemoglobin A, was shown to be doubly heterozygous for F-thalassemia and hemoglobin S. Absence of Hb A in this double heterozygote provides further evidence that in F-thalassemia the suppression of the β-chains in cis position is complete.