Review: JAK2V617F Allele Burden in Diagnosis and Therapeutic Monitoring of Myeloproliferative Neoplasms

Characterized by overproduction of differentiated cells of myeloid lineage, polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are Philadelphia chromosome negative myeloproliferative neoplasms (MPNs). Found in 95% of PV patients and 50-60% of ET and PMF patients, the JAK2V617F mutation is the most common molecular abnormality shared by the three MPN phenotypes. Although the JAK2 mutation is recommended for diagnosis of MPNs by the World Health Organization (WHO), its presence alone is insufficient to discriminate among the 3 subtypes. This implication of single mutation (JAK2V617F) in all three MPN phenotypes has long been an objective under question and several studies investigating on the gene dosage hypothesis have discovered the promising role of the JAK2V617F allele burden in MPN phenotype. The significant differences of the JAK2V617F allele burden in PV, ET and PMF patients as well its associations with specific clinical and haematological characteristics bear high utility in diagnosis, prognosis, and therapeutic monitoring. Although great strides have been achieved with the use of qPCR and new molecular biology techniques in allele burden quantification, addressing the deficits in the current understandings and further improvement of technology will be highly beneficial. Therefore, we have reviewed PubMed database from 2005 to 2022. Using keywords such as JAK2V617F mutation, Allele burden, Myeloproliferative neoplasms etc. and the present review discusses the significance of JAK2V617F allele burden in diagnosis and therapeutic monitoring of myeloproliferative neoplasms.