Two months later, and four months before the hematology evaluation, hemoglobin electrophoresis was performed to evaluate for suspected thalassemia. It returned with hemoglobin A (HbA) of 0%, hemoglobin S (HbS) of 62.5%, hemoglobin F (HbF) of 35.3%, and HbA2 of 2.2%, clinically consistent with homozygous sickle cell disease (HbSS) with hereditary persistence of fetal hemoglobin (HPFH). Here, HBA2 is linked to thalassemia.