Hemoglobinopathies and thalassemias are the most common genetic diseases, and in most cases, present as heterozygous. Due to the diversity of hemoglobin variants, specific and complementary methodologies are necessary for a precise laboratorial diagnosis, able to elucidate possible interactions between genetic polymorphisms. This case report describes an interaction between hemoglobin B2 and hemoglobin S in a Caucasian woman from the southeastern region of Brazil. This interaction was identified by electrophoresis in different pHs, high performance liquid chromatography and PCR-RFLP. As hemoglobin B2 is eluted in the same window as hemoglobin S in automatic HPLC systems and is hardly seen in alkaline electrophoresis due to its low concentration, the association must be confirmed using additional laboratorial tests, including molecular biology techniques. These tests should be included in the routine practice of hemoglobinopathy diagnosis in order to correctly identify hemoglobin variants and to know the real frequency of these mutations in the Brazilian population. Rev. Bras. Hematol. Hemoter.
Abnormal hemoglobin; hemoglobinopathies; diagnosis