Rapid decline of Philadelphia-positive metaphases after nilotinib treatment in a CML patient expressing a rare e14a3 BCR-ABL1 fusion transcript: A case report

Oncol Lett. 2019 Sep;18(3):2648-2653. doi: 10.3892/ol.2019.10558. Epub 2019 Jul 4.

Abstract

We report a case of chronic myeloid leukemia in a 52-year-old male expressing a rare e14a3 BCR-ABL1 fusion transcript. Cytogenetic analysis showed the t(9;22) translocation and multiplex RT-PCR detected an atypical fragment of approximately 230 base pairs. Using two primers recognizing exon 10 of BCR and exon 4 of ABL1, a larger PCR product was identified, cloned, sequenced and defined as an e14a3 BCR-ABL1 rearrangement. The patient was treated with nilotinib and monitored measuring cytogenetic and hematological parameters, while BCR-ABL1 transcripts were surveyed by conventional and semi-nested PCR. The patient achieved a complete hematologic response after two months of treatment followed by a complete cytogenetic remission two months later. Furthermore, PCR and semi-nested PCR failed to detect the e14a3 BCR-ABL1 mRNA after 15 and 21 months of nilotinib, respectively.

Keywords: BCR-ABL1; case report; chronic myeloid leukemia; e14a3; nilotinib.