title: Quantitative assay for the detection of the V617F variant in the Janus kinase 2 (JAK2) gene using the Luminex xMAP technology.
abstract: BACKGROUND
  The availability of clinically valid biomarkers contribute to improve the diagnosis and clinical management of diseases. A valine-to-phenylalanine substitution at position 617 (V617F) in the Janus kinase 2 (JAK2) gene has been recently associated with key signaling abnormalities in the transduction of haemopoietic growth-factor receptors and is now considered as a useful clinical marker of myeloproliferative neoplasms. Several methods have recently been reported to detect the JAK2 V617F point mutation and show variable sensitivity.
  
  
  METHODS
  Using the Luminex xMAP technology, we developed a quantitative assay to detect the JAK2V617F variant. The method was based on polymerase chain reaction (PCR) followed by hybridization to specific probes coupled with internally dyed microspheres. The assay comprises 3 steps: genomic DNA extraction, end point PCR reaction, direct hybridization of PCR fragments and quantification. It has been tested with different sources of nucleic acid.
  
  
  RESULTS
  Applied to whole blood samples, this quantitative assay showed a limit of detection of 2%. A highly sensitive allele-specific primer extension reaction performed in parallel allowed to validate the results and to identify the specimens with values below 2%.
  
  
  CONCLUSIONS
  Direct hybridization assay using the Luminex xMAP technology allows sensitive quantification of JAK2V617F from blood spots. It is simple and can be easily performed in a clinical setting.
authors.affiliation: ECOGENE-21, department of médecine, Université de Montréal, Chicoutimi Hospital, 225 rue St-Vallier, Saguenay, Province of Québec, G7H 7P2, Canada.
authors.forename: François W
authors.initials: FW
authors.lastname: Paradis
authors.forename: Raynald
authors.initials: R
authors.lastname: Simard
authors.forename: Daniel
authors.initials: D
authors.lastname: Gaudet
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D004252:DNA Mutational Analysis; D015342:DNA Probes / Q000737:chemistry; D006801:Humans; D053614:Janus Kinase 2 / Q000097:blood / Q000235:genetics*; D050505:Mutant Proteins / Q000097:blood / Q000235:genetics; D009196:Myeloproliferative Disorders / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods*; D017354:Point Mutation; D016133:Polymerase Chain Reaction
chemical_list: D015342:DNA Probes; D050505:Mutant Proteins; D053614:Janus Kinase 2