We present an acute promyelocytic leukemia (APL) patient with two subtypes of IRF2BP2-RARA, in which the IRF2BP2 gene showed completely new breakpoints. Bone marrow examination revealed morphologic features indicative of APL. However, promyelocytic leukemia-RARA fusion was not detected. A paired-end mRNA sequencing followed by RT-PCR and direct sequencing revealed two types of fusion transcripts between exon 1B of IRF2BP2 and exon 3 of RARA. The patient received all-trans retinoic acid and conventional chemotherapy, but showed resistance. This is the second report of IRF2BP2 involvement in APL, and we describe various breakpoints for the IRF2BP2-RARA fusion gene.
Keywords: Acute promyelocytic leukemia; all-trans retinoic acid; fluorescence in situ hybridization; gemtuzumab ozogamicin; interferon regulatory protein 2 binding protein 2.
© 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.