Background: The vast majority of chronic myeloid leukemia (CML) patients express the BCR-ABL transcript with the b2a2 (e13a2) and/or b3a2 (e14a2) junctions. However, some rare cases have atypical breakpoints. Methods and Results: We identified a CML patient with a unique e8a2 BCR-ABL transcript variant. It contained the first 114 nucleotides of BCR exon 8, with an insertion of 16 nucleotides from the 3′ end of ABL intron 1a, followed by ABL exon 2. Due to her uncontrolled thrombocytosis after 3 years of interferon-α treatment, the patient received imatinib at a dosage of 400 mg/day. Though achieving a sustained and complete hematological response after 3 months, she was resistant to imatinib during the entire 65-month imatinib treatment. That is, she failed to achieve major cytogenetic response and there was no significant decrease in her BCR-ABL transcript levels. Meanwhile, an M351T mutant was detected at 18 months after the start of imatinib treatment. Conclusion: ABL point mutation is also a mechanism of imatinib resistance for CML patients with the BCR-ABL transcript variant.

This content is only available via PDF.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.