Role of TET2 and ASXL1 mutations in the pathogenesis of myeloproliferative neoplasms.

Since the discovery of activating mutations in JAK2 in patients with myeloproliferative neoplasms (MPNs) in 2005, gene discovery efforts have identified additional disease alleles, which can predate or occur subsequent to acquisition of JAK2/MPL mutations. In 2009, somatic copy number loss and mutations in the genes TET2 and ASXL1 were identified in MPN patients. Genetic analysis of MPN patient cohorts with adequate sample size and clear clinical annotation are needed to understand the importance of these mutations on MPN phenotype, risk of transformation to leukemia, response to therapy, and influence on overall survival.