A case of a novel PML/RARA short fusion transcript with truncated transcription variant 2 of the RARA gene

Acute promyelocytic leukemia (APL) with atypical breakpoints in the promyelocytic leukemia (PML) and retinoic acid receptor-alpha (RARA) genes represents a rare leukemic event, which occurs preferentially in patients with variant types of the PML/RARA fusion gene. Here we report on a patient with APL with a unique PML/RARA fusion transcript that harbors a short type of this fusion gene, exhibiting unexpected results of standard PCR diagnostics. The detected transcript originates from fusion of PML exon 4 and a truncated form of transcription variant 2 of the RARA gene, with an additional 9 bp insertion. According to our knowledge, this differs from all previously described fusion transcripts.