Development of an inverse-PCR approach for characterization of the major BCR-ABL1 breakpoint sequences on genomic DNA: Proof of concept

GUTIÉRREZ, LEANDRO G.; ABELLEYRO, MIGUEL M.; RUIZ, MARÍA SOL; ANCHORDOQUI, MARÍA SOL; FREITAS, JOSEFINA; BIANCHINI, MICHELE; LARRIPA, IRENE B.; DE BRASI, CARLOS D.

CLINICAL CHEMISTRY AND LABORATORY MEDICINE

WALTER DE GRUYTER & CO

Año: 2021

1434-6621

Current consensus indicates that genomic DNA testing of BCR-ABL1 fusion gene is the best assay for evaluating residual disease in chronic myeloid leukaemia (CML). Herein, an alternative method, based on inverse PCR and Sanger sequencing, is presented to characterize the DNA sequence of the BCR-ABL1 and, eventually, the reciprocal ABL1-BCR breakpoint junctions. All six CML patients? BCR-ABL1 DNA breakpoints were fully characterized providing the indispensable information paving the way to set-up a sensitive/accurate molecular follow-up. Only four of them showed the reciprocal ABL1-BCR. Interestingly, the remnant two showed no reciprocal PCR amplification suggesting large deletions on der(9), which was confirmed by FISH studies. This novel approach constitutes a robust and cost-effective shortcut to characterize BCR-ABL1 DNA junctions allowing the setting-up of a reliable measure of residual CML cells, which represents the best information for considering the risks of stopping treatment.