A primer on genomic and epigenomic alterations in the myeloproliferative neoplasms.

The discovery of the JAK2 mutation in Philadelphia-chromosome negative myeloproliferative neoplasm (MPNs) in 2005 has heralded an era of rapid genetic discovery in the MPNs. This has lead to substantive gains in the understanding of the pathobiology of these diseases. Importantly, this has also lead to new treatment in the form of JAK inhibitors, as well as to clinical trials targeting other components thought to contribute to disease biology. However, given the number of new genomic alterations uncovered in the last several years, the relative contributions of each mutation to the development of a disease phenotype remains an area of robust investigation. Furthermore, the number of known mutations presents challenges to the practicing clinician in terms of what mutations to test for and the clinical significance of such mutations.