title: High percentage of JAK2 exon 12 mutation in Asian patients with polycythemia vera.
abstract: We examined the occurrence of JAK2(V617F) and JAK2 exon 12 mutations in a clinical cohort of polycythemia vera (PV) in Taiwan. Of 22 patients with PV, 17 (77%) had the V617F mutation, and all 5 V617F-negative patients (23%) had the exon 12 mutation. We found 3 different exon 12 mutations: 3 N542-E543del, 1 F537-K539delinsL, and 1 novel mutation, I540-E543delinsKK. Patients with V617F showed significantly higher WBC and platelet counts at diagnosis than patients with exon 12 mutations (P = .021 and P = .038, respectively). We report a surprisingly high incidence of exon 12 mutations in Taiwanese patients with PV, a result quite different from reports in the Western literature (P = .001). Our data suggest that exon 12 mutation of JAK2 in patients with PV may have an uneven geographic distribution. A clinical laboratory providing the V617F test alone may risk missing a substantial number of patients with PV in areas with a high incidence of exon 12 mutation.
authors.affiliation: Dept. of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Yeh
authors.forename: Yi-Lin
authors.initials: YL
authors.lastname: Chen
authors.forename: Hsieh-Yin
authors.initials: HY
authors.lastname: Cheng
authors.forename: Wu-Chou
authors.initials: WC
authors.lastname: Su
authors.forename: Nan-Haw
authors.initials: NH
authors.lastname: Chow
authors.forename: Tsai-Yun
authors.initials: TY
authors.lastname: Chen
authors.forename: Chung-Liang
authors.initials: CL
authors.lastname: Ho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005091:Exons; D005260:Female; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D011087:Polycythemia Vera / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013624:Taiwan
chemical_list: C507924:JAK2 protein, human; D053614:Janus Kinase 2