MPL W515L/K mutations in 343 Chinese adults with JAK2V617F mutation-negative chronic myeloproliferative disorders detected by a newly developed RQ-PCR based on TaqMan MGB probes.
Acquired mutations in the juxtamembrane region of MPL (W515L or W515K), the receptor for thrombopoietin, have been reported in patients with primary essential thrombocythemia (ET) or primary myelofibrosis (PMF). The mutations were detected by the newly developed real-time quantitative PCR (RQ-PCR) with TaqMan MGB probes and followed by the sequencing analysis. DNA samples were from 343 Chinese adults with JAK2V617F mutation-negative chronic myeloproliferative disorders (cMPDs). Reference curves were obtained using cloned fragments of MPL containing either the wild-type or MPL W515L or MPL W515K mutated sequence; the predicted sensitivity level was at least 0.5%(0.1-0.5%) for MPL W515L and 0.5%(0.2-0.5%) for MPL W515K mutant allele in a wild-type background. The detection rates of MPL W515 mutations were 3.5% in 199 ET patients (7/199), 12.5% in 24 PMF patients (3/24) and 5.6% in 36 cMPD-unclassed patients (2/36), respectively. No MPL W515 mutations were detected in 32 polycythemia vera (PV) patients, 40 chronic myeloid leukaemia (CML) patients, 12 hypereosinophilic syndrome (HES) patients and 29 normal volunteers. The mean calculated burden of MPL mutant alleles using RQ-PCR for MPL W515L/K was 24.88 +/- 14.80% (range, 1.10-56.32%). MPL W515L/K patients presented lower haemoglobin levels, compared with the patients with JAK2V617F mutation-positive cMPDs (p < 0.01). The results demonstrated that RQ-PCR was a reliable and sensitive method for large-scale screening of the MPL W515L/K mutation in patients suspected to have a cMPD. It can also provide a quantitative estimate of mutant allele burden that might be useful for both patient prognosis and monitoring response to therapy.
Ruan
Guo-Rui
GR
Peking University People's Hospital and Institute of Hematology, 11 Xi-Zhi-Men South Street, Beijing 100044, China.
Jiang
Bin
B
Li
Ling-Di
LD
Niu
Ji-Hong
JH
Li
Jin-Lan
JL
Xie
Min
M
Qin
Ya-Zhen
YZ
Liu
Yan-Rong
YR
Huang
Xiao-Jun
XJ
Chen
Shan-Shan
SS
D000328:Adult; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D004247:DNA / Q000097:blood / Q000235:genetics; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D009196:Myeloproliferative Disorders / Q000097:blood / Q000175:diagnosis* / Q000235:genetics*; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis; D053628:Receptors, Thrombopoietin / Q000235:genetics*; D012680:Sensitivity and Specificity; D015996:Survival Rate
D053628:Receptors, Thrombopoietin; C082218:MPL protein, human; D004247:DNA; C507924:JAK2 protein, human; D053614:Janus Kinase 2