Congenital dyserythropoietic anemia type II mimicking hereditary spherocytosis in Indian patient with SEC23B-Y462C mutations

Congenital Dyserythropoietic Anemia Type II With Myelofibrosis in an Adult Patient: A Report of a Rare Case With a Brief Review

Congenital dyserythropoietic anemias (CDAs) are rare hereditary disorders, of which type II CDA is the most common. Mutations in the SEC23B gene located on chromosome 20 result in this autosomal recessive disorder. In this case report, we present a case of CDA II with unique biopsy findings being detected via genetic testing. A female aged 30 years presented with major complaints of pallor weakness and easy fatiguability since childhood. The patient gave a history of 25 units of blood transfusion, the majority of which were transfused during pregnancy, followed by regular transfusions thereafter. On examination, all her vitals were in the normal range. Pallor, frontal bossing, and malocclusion of teeth were noted. Her laboratory workup showed the following: hemoglobin (Hb): 3.7 g/dl; mean corpuscular volume: 83 fl; mean corpuscular Hb: 29 g/dl; mean corpuscular Hb concentration: 34.9 g/dl; red cell distribution width: 30.4%; reticulocyte count (RC): 6.2%; corrected RC: 1.3%; lactate dehydrogenase: 441 IU/L; direct Coombs test/indirect Coombs test: negative; serum iron: 242 microgram/dl; transferrin saturation: 96.08%; ferritin: 1,880 ng/ml; and normal high-performance liquid chromatography and eosin-5'-maleimide binding test. The peripheral blood film showed normocytic normochromic anemia with anisopoikilocytosis in the form of a few spherocytes. No immature cells were seen. After obtaining the patient's consent, we performed a hereditary hemolytic anemia gene analysis test, which showed homozygous missense variation in exon 12 of the SEC23B gene. The bone marrow examination showed hyperplasia in the erythroid series with dyserythropoiesis, and surprisingly, myelofibrosis grade I-II (WHO 2017) was also observed on biopsy. Patients with CDA type II generally present with variable degrees of anemia along with pallor, icterus, splenomegaly, gallstones, and iron overload. In our case, the diagnosis of CDA type II was made at an adult age. Also, evidence of myelofibrosis was noted in our case, making it worth reporting. The use of a hereditary hemolytic anemia gene analysis panel test came as a rescue for its exact diagnosis. This case report emphasizes the role of molecular genetic testing for early and accurate diagnosis, which, in turn, could help in appropriate treatment planning and proper genetic counseling. The prevalence of CDA type II is still vaguely known; hence, extensive workup of persistent anemias and proper follow-up would be beneficial.

Congenital dyserythropoietic anaemia type II in a teenager presenting with severe anaemia

Congenital dyserythropoietic anaemia (CDA) type II is a rare disease characterised by inefficient erythropoiesis and mononuclear cytopenia. Patients generally present with extravascular haemolytic anaemia, jaundice and splenomegaly. A female patient in her mid-teens presented with severe anaemia and abdominal distention. Medical history was significant for the diagnosis of β-thalassaemia intermedia made in her infancy. However, subsequent investigations showed normal reticulocyte counts that were disproportionate to the severity of her anaemia and a negative β-thalassemia mutation analysis, leading to concerns about a specific lineage disorder. A bone marrow trephine showed features typical of CDA type II-erythroid hyperplasia with multiple binucleate erythrocytes. CDA type II has often been mistaken for other congenital or acquired forms of anaemia; this case report intends to raise awareness among clinicians to consider CDA type II as a rare but possible cause of severe anaemia in a teenager with a previous presumptive diagnosis of β-thalassaemia .

Study of pathophysiology and molecular characterization of congenital anemia in India using targeted next-generation sequencing approach

Most patients with anemia are diagnosed through clinical phenotype and basic laboratory testing. Nonetheless, in cases of rare congenital anemias, some patients remain undiagnosed despite undergoing an exhaustive workup. Genetic testing is complicated by the large number of genes that are involved in rare anemias, due to similarities in the clinical presentation. We sought to enhance the diagnosis of patients with congenital anemias by using targeted next-generation sequencing. The genetic diagnosis was performed by gene capture followed by next-generation sequencing of 76 genes known to cause anemia syndromes. Genetic diagnosis was achieved in 17 of 21 transfusion-dependent patients and undiagnosed by conventional workup. Four cases were diagnosed with red cell membrane protein defects, four patients were diagnosed with pyruvate kinase deficiency, one case of adenylate kinase deficiency, one case of glucose phosphate isomerase deficiency, one case of hereditary xerocytosis, three cases having combined membrane and enzyme defect, two cases with Diamond-Blackfan anemia (DBA) and 1 with CDA type II with 26 different mutations, of which 21 are novel. Earlier incorporation of this NGS method into the workup of patients with congenital anemia may improve patient care and enable genetic counselling.

Identification of a Novel Mutation in the SEC23B Gene Associated With Congenital Dyserythropoietic Anemia Type II Through the Use of Next-generation Sequencing Panel in an Undiagnosed Case of Nonimmune Hereditary Hemolytic Anemia

Congenital dyserythropoietic anemias (CDAs) are rare hereditary blood disorders characterized by ineffective erythropoiesis, hemolysis, and erythroblast morphologic abnormalities in the bone marrow. The 3 main types of CDA, I to III, and variant types of CDA, IV-VIII, have been described. The causative genes have been identified as CDAN1, C15ORF41, SEC23B, KIF23, KLF1, and GATA1. CDA type II is the most frequent form. Typical symptoms are jaundice, hepatosplenomegaly, mild-to-severe normocytic anemia, and inadequate reticulocyte response. We report an 18-year-old boy who had chronic mild congenital anemia, jaundice, and splenomegaly mimicking nonautoimmune hemolytic anemia since 18 months of age. Compound heterozygous mutations in SEC23B gene were detected by the use of a gene-targeted next-generation sequencing panel: the already reported missense mutation c.40C>T (p.Arg14Trp), and a new frameshift deletion (c.489_489delG, p.Val164Trpfs*3), confirming the diagnosis of CDA type II. The study underlines the molecular heterogeneity of CDA II and the importance of a precise diagnosis in rare congenital diseases such as CDA II. In consequence, it can be difficult to diagnose because of limited resources, financial constraint, and rarity of disease in the developing country. Advanced laboratories and new molecular approaches may help in diagnosing rare anemias.