Identification of a JAK2 Mutation in Polycythemia Vera

Abstract

The present invention concerns the V617F variant of the protein-tyrosine kinase JAK2, said variant being responsible for Vaquez Polyglobulia. The invention also relates to a first intention diagnostic method for erythrocytosis and thrombocytosis allowing their association with myeloproliferative disorders, or to the detection of the JAK2 V617F variant in myeloproliferative disorders allowing their reclassification in a new nosological group.

1 .- 10 . (canceled) 
     
     
         21 . An isolated nucleic acid comprising a complement of at least 12 consecutive nucleotides of sequence SEQ ID NO: 3 or 4, wherein the isolated nucleic acid comprises a thymine (t) in position 261 in SEQ ID NO: 3 or a thymine (t) at position 50 in SEQ ID NO: 4, and wherein the isolated nucleic acid further comprises a radioactive, fluorescent or enzymatic label. 
     
     
         22 . The isolated nucleic acid according to  claim 21 , wherein said nucleic acid is SEQ ID NO: 11 with a G21T mutation. 
     
     
         23 . The isolated nucleic acid according to  claim 21 , wherein the label is a radioactive label. 
     
     
         24 . The isolated nucleic acid according to  claim 21 , wherein the label is a fluorescent label. 
     
     
         25 . The isolated nucleic acid according to  claim 21 , wherein the label is an enzymatic label. 
     
     
         26 . A kit for detecting a G1849T mutation in a human Janus kinase 2 (JAK2) gene in a human tumor, wherein the kit comprises one or more primers or probes comprising a complement of an isolated nucleic acid comprising at least 12 consecutive nucleotides of sequence SEQ ID NO 3 or 4, or having at least 95% homology to at least 17 consecutive nucleotides of sequence SEQ ID NO 3 or 4, wherein the isolated nucleic acid comprises the nucleotide t 261  in SEQ ID NO 3 or t 50  in SEQ ID NO 4,
 wherein the isolated nucleic further comprises a radioactive, fluorescent or enzymatic label], for the specific detection of the presence or absence of the G1849T mutation in the human JAK2 gene,   wherein the G1849T mutation is nucleotide t 261  in SEQ ID NO 3 or t 50  in SEQ ID NO 4.   
     
     
         27 . A kit, comprising a first container containing an isolated nucleic acid and a carrier;
 wherein the isolated nucleic acid comprises a complement of at least 12 consecutive nucleotides of sequence SEQ ID NO 3 or 4, or having at least 95% homology to at least 17 consecutive nucleotides of sequence SEQ ID NO 3 or 4,   wherein the isolated nucleic acid comprises the nucleotide t 261  in SEQ ID NO 3 or t 50  in SEQ ID NO 4,   wherein the isolated nucleic acid further comprises a radioactive, fluorescent or enzymatic label.   
     
     
         28 . The kit according to  claim 26 , further comprising at least one element selected from a heat resistant polymerase for PCR amplification, one or more solutions for amplification and/or hybridization, and any reagent allowing said specific detection. 
     
     
         29 . A method, comprising:
 a) obtaining and analyzing a nucleic acid sample from a human patient, wherein the analyzing comprises:
 a1) sequencing a region of the nucleic acid sample comprising position 2343 of a complement of SEQ ID NO: 2, or 
 a2) hybridizing the nucleic acid sample with at least one probe comprising at least 10 consecutive nucleotides of a complement of SEQ ID NO: 2 comprising position 2343 of SEQ ID NO: 2 
   b) detecting the presence or absence of a thymine (T) in the JAK2 gene at position 2343 of SEQ ID NO: 2 in the nucleic acid sample;   c) if T is present at position 2343, treating the patient for polycythemia vera (PV) quantifying red cell mass, quantifying erythroid endogenous colonies or testing bone marrow of the patient; and   d) if T is absent at position 2343 of SEQ ID NO 2 quantifying red cell mass, quantifying erythroid endogenous colonies or testing bone marrow of the patient.   
     
     
         30 . The method according to  claim 29 , wherein the human patient has erythrocytosis. 
     
     
         31 . The method according to  claim 30 , wherein the human patient has a hematocrit level of higher than 51%.