The myeloproliferative disorders polycythaemia vera (PV), essential thombocythaemia (ET), and primary myelofibrosis (PMF) are clonal disorders of multipotent haematopoietic progenitors. The genetic cause of these diseases was not known until 2005, when several independent groups demonstrated that most patients with PV, ET and PMF acquire a single point mutation in the cytoplasmic tyrosine kinase JAK2 (JAK2V617F). Describe this mutation. In what types of cancer is this mutation NOT present?
- JAK2 is a proto-oncogene membrane receptor in myeloid blood cells that promotes proliferation. Constitutive activity without growth factor interaction occurs when the V617F (amino acid position 617) mutation is present.
- Mutation in non-CML myeloproliferative neoplasms.
- This mutation is NOT present in solid tumors, reactive myeloproliferative states, or lymphoid malignancies.