Identification of rare atypical BCR-ABL1 transcript: A case report.

CML is characterized by the presence of a BCR-ABL1 fusion transcript. Several guidelines have been published for its detection and molecular monitoring. Here, a case is described of chronic myeloid leukemia presenting in the blast phase with a rare variant transcript, with a discussion on possible red flags in its detection and genetic testing and description of the patient's clinical characteristics. This case highlights the pitfalls of using real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR) for diagnosis of CML, especially when the clinical picture and the test results are discordant.