Uncommon Differential Diagnosis to Homozygous Sickle Cell Disease

sickling test in the mother. The RBC characteristics in the siblings were suggestive of sickle cell-/3° thalasse¬ mia, but the Hb A, level was not elevated. This genotype represents an uncommon differential diagnosis of SS disease and sickle cell-/3° thalas¬ semia, and it should be borne in mind in cases of apparent SS disease in which a parent does not have sickle hemoglobin. The hematological and clinical features of these two cases are compared with the five previously reported cases.