A 30-year-old West African woman has lifelong mild hemolytic anemia with intermittent jaundice and moderate splenomegaly. Hemoglobin is 10.4 g/dL, MCV 78 fL, and the smear shows abundant target cells along with rod-shaped intraerythrocytic inclusions. Hemoglobin electrophoresis shows almost no HbA. The most likely genotype is:

• A Compound heterozygous HbSC
• B Heterozygous HbC trait (HbAC)
• C Homozygous HbE (HbEE)
• D Homozygous HbC (HbCC) ✓

Explanation

HbC disease (HbCC) causes a mild chronic hemolytic anemia with marked target cells and characteristic HbC crystals, which form because the beta-6 glutamic acid to lysine substitution reduces hemoglobin solubility. Electrophoresis in homozygous disease shows predominantly HbC with absent HbA. HbC trait is asymptomatic with roughly half HbA present, HbE is seen in Southeast Asians with microcytosis and few target cells, and HbSC retains some HbA-unrelated S hemoglobin with sickle features rather than pure crystal formation.

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.