Congenital Dyserythropoietic Anemia Type II Mimicking Chronic Hemolytic Anemia: A Case Report

Abstract

Congenital dyserythropoietic anaemia type II is a rare inherited disorder of ineffective erythropoiesis that can resemble chronic haemolytic anaemia. This case describes a 25-year-old female with long-standing anaemia, recurrent jaundice, previous packed red blood cell transfusions, and splenomegaly measuring 13.5 cm. Initial laboratory evaluation showed haemoglobin of 8.9 g/dL, red blood cell count of 3.37 × 10⁶/µL, haematocrit of 31.6%, increased red cell distribution width, reticulocyte count of 4.1%, markedly increased circulating nucleated red blood cells, depleted haptoglobin, and normal haemoglobin electrophoresis. The direct and indirect Coombs tests were negative. Eosin-5-maleimide binding by flow cytometry showed a 22% reduction in mean fluorescence intensity, initially suggesting hereditary spherocytosis. Bone marrow examination was performed because of the discrepancy between the haemolytic phenotype and prominent nucleated red blood cells. The aspirate showed marked erythroid hyperplasia, with a myeloid-to-erythroid ratio of 0.2:1, binucleation, multinucleation, and karyorrhexis in erythroid precursors. Pseudo-Gaucher cells were also observed. Trephine biopsy confirmed hypercellular marrow with dominant erythroid hyperplasia, severe dyserythropoiesis, normal reticulin, and markedly increased iron stores graded as 5/6. Whole exome sequencing detected a single heterozygous SEC23B mutation. The overall findings supported congenital dyserythropoietic anaemia type II as the most likely diagnosis. This case highlights diagnostic overlap with chronic haemolytic disorders and the value of marrow morphology and extended genetic evaluation when initial screening tests are misleading.