A 22-year-old asymptomatic woman is evaluated for mild microcytic anemia discovered on routine testing. Hemoglobin electrophoresis shows HbA2 of 5.2 percent, HbF 1 percent, and HbA 93.8 percent. Mentzer index (MCV/RBC count) is less than 13. What is the most likely diagnosis?

• A Beta-thalassemia minor ✓
• B Iron deficiency anemia
• C Alpha-thalassemia trait (two gene deletion)
• D Anemia of chronic disease

Explanation

Beta-thalassemia minor shows mild microcytic hypochromic anemia with a characteristic elevation of HbA2 above 3.5 percent due to relative excess of alpha chains pairing with delta chains. Iron deficiency and anemia of chronic disease have normal or reduced HbA2. Alpha-thalassemia trait also has normal HbA2 and HbF, and cannot be distinguished from iron deficiency by electrophoresis alone, which makes the raised HbA2 the decisive finding here.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.