Acute lymphoblastic leukemia with atypical bcr-abl rearrangement: a case report and literature review

Abstract

Objective To investigate the detection methods of atypical bcr-abl rearrangement with b3a3 fusion transcript, and to describe the characteristics of this fusion gene. Methods Karyotype analysis, FISH and RT-PCR were applied to detect the break point of bcr-abl fusion gene in a patient who was diagnosed as acute lymphoblastic leukemia. Results The karyotype of the patient was expressed as 45, XY,-7, t(9;22) (q34;q11). The translocation event in chromosome 9 and 22 could be successfully detected by FISH, and a rare bcr-abl rearrangement with b3a3 fusion transcript was detected by RT-PCR with specific primers. Conclusions The rare e14a3 (b3a3) fusion of bcr-abl gene is present in this patient. Clinical laboratories using commercial kits that do not cover such rare fusions are likely to generate false result, thereby declaring combination of various methods to detect fusion genes is necessary. More studies are needed to explore the function and significance of rare bcr-abl fusion genes. Key words: Leukemia, lymphoblastic, acute; bcr-abl fusion gene; Break point