The Importance of Identification of M-BCRABL Oncogene and JAK2^V617F Mutation in Myeloproliferative Neoplasms

Background: The elucidation of the genetic background of the myeloproliferative neoplasms completely changed the management of these disorders: the presence of the Philadelphia chromosome and/or the BCR-ABL oncogene is pathognomonic for chronic myeloid leukemia and identification of JAK2 gene mutations are useful in polycytemia vera (PV), essential thrombocytemia (ET) and myelofibrosis (PMF). The aim of this study was to investigate the role of molecular biology tests in the management of myeloproliferative neoplasms.

Materials and methods: We tested the blood samples of 117 patients between April 2008 and February 2013 at the Molecular Biology of UMF Târgu Mureș using RQ-PCR (for M-BCR-ABL oncogene) and/or allele-specific PCR (for JAK^2V617F mutation).

Results: Thirty-two patients presented the M-BCR-ABL oncogene, 16 of them were regularly tested as a follow-up of the administered therapy: the majority of chronic phase patients presented decreasing or stable values, while in case of accelerated phase and blast phase the M-BCR-ABL values increased or remained at the same level. Twenty patients were identified with the JAK2V617F mutation: 8 patients with PV, 4 with ET, 3 with PMF, 4 with unclassifiable chronic myeloproliferative disease and 1 patient with chronic myelomonocytic leukemia. There was no case of concomitant occurance of both molecular markers.

Conclusions: Molecular biology testing plays an important role in the management of myeloproliferative neoplasms: identification of the molecular markers confirms the final diagnosis, excluding secondary causes of abnormal blood count parameters. Regular monitoring of MBCR- ABL expression level is useful in the follow-up of therapeutic efficiency.