title: Somatic JAK-2 V617F Mutational Analysis in Polycythemia Rubra Vera: a Tertiary Care Center Experience.
abstract: BACKGROUND
  Polycythemia rubra vera (PV), being a primary polycythemia, is caused by neoplastic proliferation of erythroid, megakaryocytic and granulocytic lineages which result in panmyelosis. PV patients have a somatic acquired mutation in the Janus kinase (JAK2) pathway, rendering cell proliferation independent of the normal regulatory mechanisms that regulate erythropoiesis. The rational of this study was to determine the prevalence of the JAK-2 V617F mutation in Pakistani patients with PV.
  
  
  METHODS
  In this cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. Patients were diagnosed based on WHO criteria for PV. All were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR.
  
  
  RESULTS
  The mean age was 53.4±9.31 years (range 36-72) and the male to female ratio was 2:1. The frequency of JAK2 V617F positivity in our PV patients was found to be 92.3%. Overall 30.7% of patients were asymptomatic and remaining 69.3% presented with symptomatic disease. The mean hemoglobin was 18.1±1.9g/dl with the mean hematocrit of 55.6±8.3%. The mean total leukocyte count was 12.8±7.1x109/l and the platelet count was 511±341.9x109/l. A positive correlation of JAK2 V617F mutation was established with high TLC count (P=0.01). No correlation of JAK2 V617F could be established with age or gender (P>0.05).
  
  
  CONCLUSIONS
  The JAK2 V617F mutation frequency in our PV patients was similar to those reported internationally. Screening for the mutation in all suspected PV cases could be beneficial in differentiating patients with reactive and clonal erythrocytosis.
authors.affiliation: Department of Hematology and Blood bank, Liaquat National Hospital and Medical College, Karachi Pakistan E-mail : sadiasultan96@yahoo.com.
authors.forename: Sadia
authors.initials: S
authors.lastname: Sultan
authors.forename: Syed Mohammed
authors.initials: SM
authors.lastname: Irfan
authors.forename: Sadia Rashid
authors.initials: SR
authors.lastname: Khan
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D003430:Cross-Sectional Studies; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D007958:Leukocyte Count / Q000379:methods; D008297:Male; D008875:Middle Aged; D010976:Platelet Count / Q000379:methods; D017354:Point Mutation / Q000235:genetics*; D011086:Polycythemia / Q000235:genetics; D011087:Polycythemia Vera / Q000235:genetics*; D012189:Retrospective Studies; D062606:Tertiary Care Centers
chemical_list: C507924:JAK2 protein, human; D053614:Janus Kinase 2