Cytogenetics of myeloproliferative neoplasms.

The introduction of JAK2 mutation testing has changed dramatically the diagnostic algorithms for myeloproliferative neoplasms (MPNs) but there is still a place for conventional cytogenetic analysis in the initial work-up of MPN cases, particularly as this group of myeloid disorders has been expanded to include chronic eosinophilic leukaemia and myeloid neoplasms with abnormalities of the PDGFRA, PDGFRB, and FGFR1 genes. Mastocytosis is also included under the umbrella of MPN but the cytogenetic abnormalities observed usually reflect any associated clonal haematological non-mast cell lineage disease.