title: [JAK2 exon 12 mutations in patients with Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms].
abstract: OBJECTIVE
  To investigate JAK2 exon 12 mutations in patients with Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms (MPN) and the clinical characteristics of patients with JAK2 exon 12 mutants.
  
  
  METHODS
  Allele-specific PCR (AS-PCR) was applied to identify JAK2 V617F mutation. Genomic DNA corresponding to exon 12 of JAK2 gene and epigenetic regulator gene (TET2, ASXL1, EZH2) were amplified by polymerase chain reaction (PCR). Identification of mutants was by direct sequencing and classification of mutation types by sequencing followed by plasmid cloning. SNP genotyping of two 46/1 tag SNPs, rs12340895 and rs10974944, was analyzed using commercially available Taqman assays on the 7500HT real-time PCR instrument according to standard protocols.
  
  
  RESULTS
  No JAK2 exon 12 mutation was detected in patients with ET, PMF or JAK2 V617F positive PV. Among 13 JAK2 V617F negative PV patients, JAK2 exon 12 mutation was detected as N542-E543del in 2(15.4%) patients who presented with a phenotype of predominant erythrocytosis and erythroid colonic grown from their bone marrow samples in the absence of exogenous EPO, reduced serum erythropoietin (EPO) level, and no mutations in TET2, ASXL1 or EZH2 genes. One of the affected patients was heterozygous for 46/1 but the second was negative for this haplotype.
  
  
  CONCLUSIONS
  There was no need to detect JAK2 exon 12 mutation in ET, PMF or MPN-U patients without JAK2 V67F mutation. Ph negative MPN patients with JAK2 exon 12 mutations had somewhat unique clinical and laboratory features.
authors: Institute of Hematology and Blood Diseases Hospital, CAMS & PUMC, The State Key Laboratory of Experimental Hematology, Tianjin, China.
authors: Jie-Yu
authors: JY
authors: Wang
authors: Xiao-Fei
authors: XF
authors: Ai
authors: Jun-Qing
authors: JQ
authors: Xu
authors: Qing-Hua
authors: QH
authors: Li
authors: Ze-Feng
authors: ZF
authors: Xu
authors: Tie-Jun
authors: TJ
authors: Qin
authors: Yue
authors: Y
authors: Zang
authors: Zhi-Jian
authors: ZJ
authors: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019046:Bone Marrow Neoplasms / Q000235:genetics*; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D005838:Genotype; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000235:genetics*; D010677:Philadelphia Chromosome; D055815:Young Adult
chemical_list: C507924:JAK2 protein, human; D053614:Janus Kinase 2