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