title: Characterization of a novel variant BCR-ABL1 fusion transcript in a patient with chronic myeloid leukemia: Implications for molecular monitoring.
abstract: Molecular monitoring of BCR-ABL1 transcript levels using quantitative polymerase chain reaction is an essential part of the modern management of chronic myeloid leukemia patients treated with tyrosine kinase inhibitors. Establishing the diagnostic BCR-ABL1 fusion transcript is necessary in order to select appropriate primers and probes for such monitoring. A case is described in which quantitative polymerase chain reaction failed to detect the presence of BCR-ABL1 fusion transcript in a Philadelphia chromosome-positive chronic myeloid leukemia patient. Further investigation demonstrated a novel in-frame BCR-ABL1 fusion transcript with a breakpoint in BCR exon 13 and insertion of a sequence of ABL1 intron 1, therefore enabling subsequent molecular monitoring. This case highlights the requirement for characterization of the BCR-ABL1 transcript type at chronic myeloid leukemia diagnosis. Issues concerning standardized methodological approaches and interpretation of transcript levels in such rare cases are discussed.
authors.affiliation: Cancer Molecular Diagnostics, St. James's Hospital, Dublin, Ireland.
authors.forename: Mireille
authors.initials: M
authors.lastname: Crampe
authors.affiliation: Cancer Molecular Diagnostics, St. James's Hospital, Dublin, Ireland.
authors.forename: Karl
authors.initials: K
authors.lastname: Haslam
authors.affiliation: Department of Clinical Genetics, Our Lady's Children's Hospital, Dublin, Ireland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Kelly
authors.affiliation: Department of Hematology, St. James's Hospital, Dublin, Ireland.
authors.forename: Eibhlin
authors.initials: E
authors.lastname: Conneally
authors.affiliation: Cancer Molecular Diagnostics, St. James's Hospital, Dublin, Ireland. Electronic address: slangabeer@stjames.ie.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Langabeer
mesh_terms: D000328:Adult; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008297:Male
chemical_list: D016044:Fusion Proteins, bcr-abl
keywords: BCR-ABL1; Chronic myeloid leukemia; Molecular monitoring; Variant