Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 5 3 2011 09 15 16 20 Mehrdad Payandeh Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran. Farhad Shaveisi Zadeh Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, Iran Mohammad Erfan Zare Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran Kamran Mansouri Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran Reza Khodarahmi Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran Saeed Alimoradi Paramedical Faculty, Kermanshah university of Medical Sciences, Kermanshah, Iran Hoshang Yousefi Research Center of Iranian Blood Transfusion Organization, Kermanshah, Iran. Fatemeh Darabi Paramedical Faculty, Kermanshah University of Medical Sciences, kermanshah, Iran 2015 10 01 Introduction: The myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases characterized by excessive production of blood cells by  hematopoietic precursors. Typically, they include polycythemia vera (PV), essential thrombocythemia (ET), idiopathic myelofibrosis(IMF), and chronic myeloid leukemia (CML). Philadelphia chromosome is the final diagnostic test for CML. Recently, JAK2 mutation introduced as a diagnostic marker for other MPNs. The aim of this study is evaluation of Philadelphia chromosome in CML patients and JAK2 mutation in MPNs patients that had been referred to a hematology/oncology clinic in Kermanshah between 2010-2011. Material and methods: In this study we evaluated common genetic disorders in 124 MPNs patients. Expression of B2A2 BCR-ABL mRNA in peripheral blood leucocytes was detected by a reverse transcriptase polymerase chain reaction (RT-PCR) for CML patients. Also, we used AS-RT-PCR method for the detection of the JAK2 mutation for all of 124 patients. Results: We found 93.7% CML patients (60/64) with positive Philadelphia chromosome. Also, 85% PV patients (17/20), 46.6% ET patients (14/30) and 40% IMF patients (4/10) had JAK2 mutation. Notably, we found a CML patient with positive Philadelphia chromosome and JAK2 mutation. Conclusion: Diagnosis of MPNs is often complex and expensive but, JAK2 mutation is a sensitive test, relatively cost-effective for proving clonality in MPNs. Also, more studies are required to determine the exact frequency and prognostic role of the JAK2 mutation in Philadelphia positive CML patients. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/282 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/282/275