Background: Hyperthyroidism can lead to diverse hematological disorders, such as microcytosis and a mild increase in hemoglobin A2 fraction.
Methods: This study reported a 31-year-old woman of Moroccan origin recently diagnosed with Graves' disease. Her blood tests revealed microcytosis, hypochromia, and a normal ferritin level. A phenotypic analysis of hemo-globin was performed using two techniques: capillary electrophoresis and reversed-phase high performance liquid chromatography.
Results: Both techniques indicated a slight increase in hemoglobin A2 level. These results initially suggested het-erozygous beta-thalassemia, eventually correlating with the concurrent presence of Graves' disease, as evidenced by the normalization of hemoglobin A2 level following treatment.
Conclusions: This case highlights the importance of having clinical, biological, and therapeutic data for a relevant interpretation of a phenotypic hemoglobin study.