<prompt> Following are features of polycythemia rubra vera except -Increased red cell massNormal aerial oxygen sturationHigh leucocyte alkaline phosphatase scoreNone  <response>: Polycythaemia rubra vera results in increased red cell mass,aerial oxygen saturation 92, raised neutrophil alkaline phosphatase scores.Reference :Harsh mohan textbook of pathology sixth editionpg no 359. 