Primary MyelofibrosisJanus Kinase 2Thrombocythemia, EssentialPolycythemia VeraMyeloproliferative DisordersReceptors, ThrombopoietinSplenomegalyBone and BonesBone MarrowMyelodysplastic-Myeloproliferative DiseasesThrombocytosisSea-Blue Histiocyte SyndromeMegakaryocytesMutationBone RemodelingPrognosisKaryotypingHematopoiesis, ExtramedullaryPlatelet CountWorld Health OrganizationBone DensityMutation, MissenseReticulinBone ResorptionOsteosclerosisBone Marrow CellsAmino Acid SubstitutionDisease ProgressionSurvival Rate