Diagnosis: Congenital Dyserythropoietic Anemia Type 2 Due to Compound Heterozygote Mutation in SEC23B Gene

摘要

A clinical diagnosis of congenital dyserythropoietic anemia (CDA) type 2 was established after exclusion of other causesassociated with dyserythropoiesis and ineffective erythropoiesis, including thalassemia syndromes, vitamin B12 and folatedeficiencies, myelodysplastic syndrome, and sideroblastic anemia. Molecular analyses for CDA type 2 revealed compoundheterozygote mutations in the SEC23B gene (c.325G >A, p.Glu109Lys in exon 4 and c.938 G >A, p.Arg313His in exon 8).CDA is a heterogeneous group of rare hereditary disorders of ineffective erythropoiesis and dyserythropoiesis characterizedby morphologically abnormal erythroid precursors in the bone marrow. Non-erythroid hematopoietic cell morphology is normal[1]. Type 2 (CDA 2), the most common type, is autosomal recessive and typically shows marked dyserythropoiesis characterizedby binucleated and multinucleated normoblasts with erythroid hyperplasia [2,3,4]. Most patients with CDA 2 show variabledegrees of anemia, usually have jaundice, and may have hepatosplenomegaly. Our patient was diagnosed as having CDA type 2by the presence of anemia, icterus, hepatosplenomegaly, binucleated and trinucleated erythroid precursors in the bone marrow,and positive SEC23B mutation.