53761-3

LOINC code 53761-3 identifies "JAK2 gene.p.Val617Phe mutant/Normal in Blood or Tissue by Molecular genetics method". The JAK2 gene is located on chromosome 9 and the V617F point mutation causes valine to phenylalanine substitution at position 617. JAK2 is a cytoplasmic protein, with the V617F mutation resulting in constitutive JAK2 activity and enhanced JAK2-signal transducers and activators of transcription signaling. The V617F point mutation causes the activation of these pathways, leading to uncontrolled cell proliferation, resulting in myeloproliferative disorders. This mutation is seen in most patients with polycythemia vera and about half of the patients with essential thromobcytopenia and idiopathic myelofibrosis. Mutation has also been found in some patients with Philadelphia chromosome negative Chronic Myelogenous Leukemia(CML), Chronic Myelomonocytic Leukemia(CMML), chronic neutrophilic leukemia, megakaryocytic leukemia, and some patients with myelodysplastic syndrome(MDS). Information from the American Society of Hematology (www.hematology.org; accessed 2007 03 02.) and ARUP Laboratories (2007 10 24).

This code measures JAK2 gene.p.Val617Phe mutant/normal in Bld/Tiss. It belongs to the MOLPATH.MUT class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.