Whole-exome analysis to detect congenital hemolytic anemia mimicking congenital dyserythropoietic anemia

Motoharu Hamada, Sayoko Doisaki, Yusuke Okuno, Hideki Muramatsu, Asahito Hama, Nozomu Kawashima, Atsushi Narita, Nobuhiro Nishio, Kenichi Yoshida, Hitoshi Kanno, Atsushi Manabe, Takashi Taga, Yoshiyuki Takahashi, Satoru Miyano, Seishi Ogawa, Seiji Kojima

Congenital dyserythropoietic anemia (CDA) is a heterogeneous group of rare congenital disorders characterized by ineffective erythropoiesis and dysplastic changes in erythroblasts. Diagnosis of CDA is based primarily on the morphology of bone marrow erythroblasts; however, genetic tests have recently become more important. Here, we performed genetic analysis of 10 Japanese patients who had been diagnosed with CDA based on laboratory findings and morphological characteristics. We examined 10 CDA patients via central review of bone marrow morphology and genetic analysis for congenital bone marrow failure syndromes. Sanger sequencing for CDAN1, SEC23B, and KLF1 was performed for all patients. We performed whole-exome sequencing in patients without mutation in these genes. Three patients carried pathogenic CDAN1 mutations, whereas no SEC23B mutations were identified in our cohort. WES unexpectedly identified gene mutations known to cause congenital hemolytic anemia in two patients: canonical G6PD p.Val394Leu mutation and SPTA1 p.Arg28His mutation. Comprehensive genetic analysis is warranted for more effective diagnosis of patients with suspected CDA.