Hemoglobin E Disease Identified During Evaluation of Persistent Microcytosis and Thrombocytosis: A Case Report

Abstract

Hemoglobin E (HbE) disease may present with marked microcytosis and mild anemia, mimicking iron deficiency and complicating the diagnostic process when thrombocytosis coexists. This case report aimed to describe the diagnostic evaluation and clinical implications of suspected homozygous HbE disease in a woman of reproductive age. A descriptive review of the medical records of a 28-year-old woman referred following pregnancy loss was conducted. Data included serial complete blood counts, iron studies, peripheral blood smear findings, hemoglobin electrophoresis, JAK2 mutation testing, and abdominal ultrasonography. Hemoglobin levels increased from 9.9 to 11.8 g/dL, whereas mean corpuscular volume remained low at 59.4–63.2 fL, and platelet counts ranged from 530 to 709 × 10³/µL. Hemoglobin analysis revealed an HbE fraction of 93.4% with no detectable HbA, a pattern consistent with homozygous HbE disease. Iron studies did not indicate severe iron deficiency. JAK2 mutation testing yielded negative results, and abdominal ultrasonography revealed no hepatosplenomegaly. Thrombocytosis was considered potentially reactive; however, its underlying cause remained undetermined, and a clonal hematologic disorder could not be excluded. Molecular confirmation of the HbE genotype was unavailable. This case highlights the diagnostic value of hemoglobin analysis in patients with persistent microcytosis and emphasizes the importance of partner screening and genetic counseling. The available clinical and laboratory findings do not establish a direct causal relationship between HbE disease and the preceding pregnancy loss.