ABSTRACT The chronic myeloproliferative neoplasms (CMPN) are a group of clonal hematopoietic stem cell disorders in which large numbers of red blood cells, white blood cells, or platelets grow and spread excess in the bone marrow and the pe- ripheral blood. Cytogenetic analysis of the t (9:22) and molecular detection of BCR/ABL is the main diagnostic criteria in Philadelphia positive CMPN (CML). The identification of non-receptor tyrosine kinase JAK2 mutations (exon 14 JAK2 V617F and exon 12) have significantly contributed to our understanding of the molecular mechanisms in the pathogenesis of Philadelphia negative CMPN such as polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients. According to the revised WHO classification, JAK2 mutation is considered as a major diagnostic and clonal marker in Philadelphia negative CMPN which will play a major role in designing personal- ized treatments for the disease. JAK2 V617F mutation frequency is unknown in Saudi Arabia. Therefore, investigation of the JAK2 V617F mutation was carried out in DNA samples from 78 peripheral blood specimens corresponding to patients with polycythemia vera (PV) (n = 11), Chronic myeloid leukemia (CML) (n = 45), essential thrombocythemia (ET) (n = 10), idiopathic myelofibrosis (MF) (n = 12). We used polymerase chain reaction and direct DNA sequencing to detect the JAK2 mutation. Overall, the incidence of the JAK2 V617F mutation was 91% in PV, 40% in ET, and 25% in MF. This approach proved to be reliable and more sensitive in detecting the mutation. Two essential findings arose from our study. First, this technique could be carried out with DNA samples, even partially degraded, from routinely processed BM or peripheral blood specimens. Second, after correlation with morphological features, it turned out that the characteristics of the megakaryocytes were more specific than the mutational status of JAK2 in characterizing ET and PMF. Concerning PV, as expected, the incidence of the JAK2 mutation was higher, but the morphological criteria were misleading in some cases, strongly suggesting that the combination of both morphology and molecular data would enable the characterization of virtually all cases. JAK2 V617F mutation frequency along with accurate morphological characterization is very reliable tool in diagnosing and classifying CMPN in Saudi patients.
Cite this paper
M. Gari, F. Al-Sayes, F. Ahmed, A. Peerzada, A. Abuzenadah, L. Mira, M. Al-Qahtani, A. Dallol, A. Chaudhary, M. Mahnashi and G. Damanhouri, "JAK2 Mutations in Chronic Myeloproliferative Neoplasm; Towards the Application of Personalized Treatments for Saudi Patients," Open Journal of Blood Diseases, Vol. 2 No. 2, 2012, pp. 17-21. doi: 10.4236/ojbd.2012.22004.
 A. Tefferi and D. G. Gilliland, “Oncogenes in Myeloproliferative Disorders,” Cell Cycle, Vol. 6, No. 5, 2007, pp. 550-566. doi:10.4161/cc.6.5.3919
 C. R. Bartram, A. de Klein, A. Hagemeijer, T. van Agthoven, A. Geurts van Kessel, D. Bootsma, G. Grosveld, M. A. Ferguson-Smith, T. Davies, M. Stone, N. Heisterkamp, J. R. Stephenson and J. Groffen, “Translocation of C-Ab1 Oncogene Correlates with the presence of a Philadelphia Chromosome in Chronic Myelocytic Leukaemia,” Nature, Vol. 306, No. 5940, 1983, pp. 277-280.
 J. D. Rowley, “A New Consistent Chromosomal Abnormality in Chronic Myelogenous Leukaemia Identified by Quinacrine Fluorescence and Giemsa Staining,” Nature, Vol. 243, 1973, pp. 290-293. doi:10.1038/243290a0
 C. James, V. Ugo, J. P. Le Couedic, J. Staerk, F. Delhommeau, C. Lacout, L. Garcon, H. Raslova, R. Berger, A. Bennaceur-Griscelli, J. L. Villeval, S. N. Constantinescu, N. Casadevall and W. Vainchenker, “A Unique Clonal JAK2 Mutation Leading to Constitutive Signalling Causes Polycythaemia Vera,” Nature, Vol. 434, 2005, pp. 1144-1148. doi:10.1038/nature03546
 R. L. Levine, M. Loriaux, B. J. Huntly, M. L. Loh, M. Beran, E. Stoffregen, R. Berger, J. J. Clark, S. G. Willis, K. T. Nguyen, N. J. Flores, E. Estey, N. Gattermann, S. Armstrong, A. T. Look, J. D. Griffin, O. A. Bernard, M. C. Heinrich, D. G. Gilliland, B. Druker and M. W. Deininger, “The JAK2V617F Activating Mutation Occurs in Chronic Myelomonocytic Leukemia and Acute Myeloid Leukemia, But Not in Acute Lymphoblastic Leukemia or Chronic Lymphocytic Leukemia,” Blood, Vol. 106, No. 10, 2005, pp. 3377-3379.
 R. L. Levine, M. Wadleigh, J. Cools, B. L. Ebert, G. Wernig, B. J. Huntly, T. J. Boggon, I. Wlodarska, J. J. Clark, S. Moore, J. Adelsperger, S. Koo, J. C. Lee, S. Gabriel, T. Mercher, A. D’Andrea, S. Frohling, K. Dohner, P. Marynen, P. Vandenberghe, R. A. Mesa, A. Tefferi, J. D. Griffin, M. J. Eck, W. R. Sellers, M. Meyerson, T. R. Golub, S. J. Lee and D. G. Gilliland, “Activating Mutation in the Tyrosine Kinase JAK2 in Polycythemia Vera, Essential Thrombocythemia, and Myeloid Metaplasia with Myelofibrosis
 I. Dalal, E. Arpaia, H. Dadi, S. Kulkarni, J. Squire and C. M. Roifman, “Cloning and Characterization of the Human Homolog of Mouse Jak2,” Blood, Vol. 91, No. 3, 1998, pp. 844-851.
 E. Lippert, M. Boissinot, R. Kralovics, F. Girodon, I. Dobo, V. Praloran, N. Boiret-Dupre, R. C. Skoda and S. Hermouet, “The JAK2-V617F Mutation Is Frequently Present at Diagnosis in Patients with Essential Thrombocythemia and Polycythemia Vera,” Blood, Vol. 108, 2006, pp. 1865-1867. doi:10.1182/blood-2006-01-013540
 F. Passamonti, E. Rumi, D. Pietra, M. G. Della Porta, E. Boveri, C. Pascutto, L. Vanelli, L. Arcaini, S. Burcheri, L. Malcovati, M. Lazzarino and M. Cazzola, “Relation between JAK2 (V617F) Mutation Status, Granulocyte Activation, and Constitutive Mobilization of CD34+ Cells into Peripheral Blood in Myeloproliferative Disorders,” Blood, Vol. 107, 2006, pp. 3676-3682.
 A. Tefferi, T. L. Lasho, S. M. Schwager, J. S. Strand, M. Elliott, R. Mesa, C. Y. Li, M. Wadleigh, S. J. Lee and D. G. Gilliland, “The Clinical Phenotype of Wild-Type, Heterozygous, and Homozygous JAK2V617F in Polycythemia Vera,” Cancer, Vol. 106, No. 3, 2006, pp. 631-635. doi:10.1002/cncr.21645
 R. Tibes and R. A. Mesa, “Myeloproliferative Neoplasms 5 Years after Discovery of JAK2V617F: What Is the Impact of JAK2 Inhibitor Therapy?” Leukemia & lymphoma, Vol. 52, No. 7, 2011, pp. 1178-1187.
 J. W. B. R. Vardiman and N. L. Harris, “WHO Histological Classification of Chronic Myeloproliferative Diseases,” In: H. Jaffees, H. Stein and J. W. Vardiman, Eds., World Health Organization Classification of Tumors: Tumours of the Haematopoietic and Lymphoid Tissues, 2001 Edition, International Agency for Research on Cancer (IARC) Press, Lyon, France, 2001, pp. 17-44.
 World Medical Association General Assembly, “World Medical Association Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Subjects,” Journal International de Bioethique International Journal of Bioethics, Vol. 15, No. 1, 2004, pp. 124-129.
 J. Chasseriau, J. Rivet, F. Bilan, J. C. Chomel, F. Guilhot, N. Bourmeyster and A. Kitzis, “Characterization of the Different BCR-ABL Transcripts with a Single Multiplex RT-PCR,” The Journal of molecular diagnostics, Vol. 6, 2004, pp. 343-347. doi:10.1016/S1525-1578(10)60530-2
 N. L. Harris, E. S. Jaffe, J. Diebold, G. Flandrin, H. K. Muller-Hermelink, J. Vardiman, T. A. Lister and C. D. Bloomfield, “The World Health Organization Classification of Neoplasms of the Hematopoietic and Lymphoid Tissues: Report of the Clinical Advisory Committee meeting-Airlie House, Virginia, November, 1997,” The hematology journal, Vol. 1, No. 1, 2000, pp. 53-66.
 C. James, V. Ugo, N. Casadevall, S. N. Constantinescu and W. Vainchenker, “A JAK2 Mutation in Myeloproliferative Disorders: Pathogenesis and Therapeutic and Scientific Prospects,” Trends in molecular medicine, Vol. 11, No. 12, 2005, pp. 546-554.
 R. Kralovics, F. Passamonti, A. S. Buser, S. S. Teo, R. Tiedt, J. R. Passweg, A. Tichelli, M. Cazzola and R. C. Skoda, “A Gain-Of-Function Mutation of JAK2 in Myeloproliferative Disorders,” The New England journal of medicine, Vol. 352, 2005, pp. 1779-1790.
 E. Kouroupi, K. Zoi, N. Parquet, C. Zoi, J. J. Kiladjian, V. Grigoraki, W. Vainchenker, F. Lellouche, C. Marzac, M. H. Schlageter, C. Dosquet, L. M. Scott, P. Fenaux, D. Loukopoulos, C. Chomienne and B. Cassinat, “Mutations in Exon 12 of JAK2 Are Mainly Found in JAK2 V617F-Negative Polycythaemia Vera Patients,” British Journal of Haematology, Vol. 142, 2008, pp. 676-679.
 L. M. Scott, W. Tong, R. L. Levine, M. A. Scott, P. A. Beer, M. R. Stratton, P. A. Futreal, W. N. Erber, M. F. McMullin, C. N. Harrison, A. J. Warren, D. G. Gilliland, H. F. Lodish, A. R. Green, “JAK2 Exon 12 Mutations in Polycythemia Vera and Idiopathic Erythrocytosis,” The New England Journal of Medicine, Vol. 356, 2007, pp. 459-468. doi:10.1056/NEJMoa065202
 A. M. Vannucchi, E. Antonioli, P. Guglielmelli, A. Rambaldi, G. Barosi, R. Marchioli, et al., “Clinical Profile of Homozygous JAKV2 V617F Mutation in Patients with Polycythemia Vera or Essential Thrombocythemia,” Blood, Vol. 110, 2007, pp. 840-846.