title: Adult acute lymphoblastic leukemia with a rare b3a3 type BCR/ABL1 fusion transcript.
abstract: The Philadelphia chromosome (Ph) is the most frequent chromosomal abnormality detected in adult acute lymphoblastic leukemia (ALL). This chromosome forms the BCR/ABL1 fusion gene; thus, ABL1 exon a2 is generally used as a primer-binding region for the detection of the fusion transcript via reverse transcription polymerase chain reaction (RT-PCR). We observed a rare case of adult Ph-positive (Ph(+)) ALL, in which the BCR/ABL1 fusion transcript was not detected using the ABL1 exon a2 region primer. However, we were able to isolate a PCR product by RT-PCR with the BCR exon 13 (b2) and ABL1 exon a3 primers. Analysis of the sequence of the RT-PCR product revealed that the fusion point was between BCR exon 14 (b3) and ABL1 exon a3, and that the transcript lacked ABL1 exon a2. The patient achieved cytogenetic remission through combination chemotherapies, but relapse occurred before hematopoietic stem cell transplantation and the patient died 11 months after the initialization of chemotherapies. If the BCR/ABL1 fusion transcript is undetected with the ABL1 exon a2 region primer in Ph(+) ALL cases, an RT-PCR analysis that can detect the b3a3 type BCR/ABL1 fusion transcript should be considered to improve diagnosis.
authors: Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan. Electronic address: kuritadaisuke2@gmail.com.
authors: Daisuke
authors: D
authors: Kurita
authors: Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan. Electronic address: hatta.yoshihiro@nihon-u.ac.jp.
authors: Yoshihiro
authors: Y
authors: Hatta
authors: Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan; Division of Hematology and Oncology, Kasukabe Municipal Hospital, Kasukabe-shi, Japan.
authors: Atsuko
authors: A
authors: Hojo
authors: Division of Hematology and Oncology, Kasukabe Municipal Hospital, Kasukabe-shi, Japan.
authors: Yoshimasa
authors: Y
authors: Kura
authors: Division of Hematology and Oncology, Kasukabe Municipal Hospital, Kasukabe-shi, Japan.
authors: Umihiko
authors: U
authors: Sawada
authors: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama-shi, Japan.
authors: Yoshinobu
authors: Y
authors: Kanda
authors: Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
authors: Masami
authors: M
authors: Takei
mesh_terms: D000328:Adult; D020732:Cytogenetic Analysis / Q000379:methods; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D010677:Philadelphia Chromosome; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*
chemical_list: C581634:BCR-ABL1 fusion protein, human; D016044:Fusion Proteins, bcr-abl
keywords: Acute lymphoblastic leukemia; BCR/ABL1 fusion transcripts; Philadelphia chromosome