Second case of CML with aberrant BCR-ABL fusion transcript (e8/a2) with insertion of an inverted ABL intron 1b sequence.

We found a case of Ph-positive chronic myelogenous leukemia (CML) patient with an atypical BCR-ABL transcript that was undetectable by a routine reverse transcription polymerase chain reaction (RT-PCR) for major BCR-ABL. Additional RT-PCR and sequence analyses have demonstrated that the aberrant transcript consists of a fusion of BCR exon 8 (e8) and ABL exon 2 (a2) with an insertion of a 55-bp inverted sequence of intron 1b between them. The nucleotide sequences of the aberrant transcript were identical to those of a previously reported CML patient. These are the only two CML cases in the literature with identical aberrant BCR-ABL transcripts.