Relier Pairs polycythemia veraVersion en ligne information about thus blood cancer par Kennedy Ellis 1 what do you experience? 2 polycythemai vera 3 what does polycythemia cause? 4 enlarged spleen 5 drawing blood 6 the mutation in which gene causes this blood cancer increased number of red blood cells helps fight infection and filter unwanted material and gets bigger when there is too much RBCs heart attack or stroke itchiness, headches, dizziness, bleeding/bruising, weakness, fatigue janus kinase 2 (JAK2) helps reduce # of RBCs