Rapid Identification of Fusion in Acute Lymphoblastic Leukemia.

INTRODUCTION

is rearranged and overexpressed in a subgroup of acute lymphoblastic leukemia (ALL) with B-precursor phenotype, with a favorable outcome. Even though characteristic gene expression signature as well as surface expression of CD2/CD371 could be a hallmark of -rearranged ALL, actual detection of rearrangement is, however, largely dependent on whole transcriptome analysis due to the highly repetitive nature of gene loci and insertion as the main mechanism of fusion gene formation.

METHODS

Polymerase chain reactions (PCRs) with several combinations of multiplex primers located on and gene loci were used for the detection of , which represents more than 90% of fusion.

RESULTS

fusion was successfully detected in three out of 50 ALL cases analyzed by standard PCR, and these positive cases showed variable insertion of into the locus. In all patients, sequences of unknown origin were observed at the junction of and sequences, indicating the role of the V(D)J recombination mechanism in fusion gene formation. Although is tandemly repeated at its locus, only a single copy of the sequence was detected at the locus in two of the three -rearranged ALL cases. As previously reported, both CD2 and CD371 were positive in all cases with :: fusion, suggesting that the combination of CD2 and CD371 could be a more reliable marker for detecting the presence of this fusion.

CONCLUSIONS

Identification of :: fusion in ALL could be possible more easily by a simple multiplex PCR strategy.