Rapid detection of JAK2 V617F mutation using high-resolution melting analysis with LightScanner platform.
ABSTRACT Detection of the JAK2 mutation has recently been included under the essential diagnostic criteria for myeloproliferative neoplasm (MPN). High-resolution melt (HRM) curve analysis, a nongel-based, automated system, is introduced as a means of mutation scanning without the requirement of any post-PCR handling.
We studied the sensitivity and reproducibility of LightScanner™ platform in the detection of JAK2 V617F mutation and the availability for diagnostic use in MPN.
The reproducible sensitivity of HRM analysis with LightScanner™ platform was 5% for the detection of JAK2 V617F mutation. In the test of blind screening of 105 samples (48 Ph- MPN and 57 Ph+ chronic myeloid leukemia), the identical judgement was interpreted by two blinded investigators. HRM analysis of all cases was fully concordant with the results of PCR-RFLP and direct sequencing.
The HRM method developed here is an extremely sensitive, accurate and reliable technique and allows high-throughput, fast pre-screening to select for sequencing only those specimens that most likely contain mutant JAK2 V617F allele(s).
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ABSTRACT: Polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are clonal myeloproliferative disorders arising from a multipotent progenitor. The loss of heterozygosity (LOH) on the short arm of chromosome 9 (9pLOH) in myeloproliferative disorders suggests that 9p harbors a mutation that contributes to the cause of clonal expansion of hematopoietic cells in these diseases. We performed microsatellite mapping of the 9pLOH region and DNA sequencing in 244 patients with myeloproliferative disorders (128 with polycythemia vera, 93 with essential thrombocythemia, and 23 with idiopathic myelofibrosis). Microsatellite mapping identified a 9pLOH region that included the Janus kinase 2 (JAK2) gene. In patients with 9pLOH, JAK2 had a homozygous G-->T transversion, causing phenylalanine to be substituted for valine at position 617 of JAK2 (V617F). All 51 patients with 9pLOH had the V617F mutation. Of 193 patients without 9pLOH, 66 were heterozygous for V617F and 127 did not have the mutation. The frequency of V617F was 65 percent among patients with polycythemia vera (83 of 128), 57 percent among patients with idiopathic myelofibrosis (13 of 23), and 23 percent among patients with essential thrombocythemia (21 of 93). V617F is a somatic mutation present in hematopoietic cells. Mitotic recombination probably causes both 9pLOH and the transition from heterozygosity to homozygosity for V617F. Genetic evidence and in vitro functional studies indicate that V617F gives hematopoietic precursors proliferative and survival advantages. Patients with the V617F mutation had a significantly longer duration of disease and a higher rate of complications (fibrosis, hemorrhage, and thrombosis) and treatment with cytoreductive therapy than patients with wild-type JAK2. A high proportion of patients with myeloproliferative disorders carry a dominant gain-of-function mutation of JAK2.New England Journal of Medicine 05/2005; 352(17):1779-90. · 51.66 Impact Factor
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ABSTRACT: Myeloproliferative disorders are characterized by clonal expansion of normal mature blood cells. Acquired mutations giving rise to constitutive activation of the JAK2 tyrosine kinase has been shown to be present in the majority of patients. Since the demonstration that the V617F mutation in the exon 14 of the JAK2 gene is present in about 90% of patients with Polycythemia Vera (PV), the detection of this mutation has become a key tool for the diagnosis of these patients. More recently, additional mutations in the exon 12 of the JAK2 gene have been described in 5 to 10% of the patients with erythrocytosis. According to the updated WHO criteria the presence of these mutations should be looked for in PV patients with no JAK2 V617F mutation. Reliable and accurate methods dedicated to the detection of these highly variable mutations are therefore necessary. For these reasons we have defined the conditions of a High Resolution DNA Melting curve analysis (HRM) method able to detect JAK2 exon 12 mutations. After having validated that the method was able to detect mutated patients, we have verified that it gave reproducible results in repeated experiments, on DNA extracted from either total blood or purified granulocytes. This HRM assay was further validated using 8 samples bearing different mutant sequences in 4 different laboratories, on 3 different instruments. The assay we have developed is thus a valid method, adapted to routine detection of JAK2 exon 12 mutations with highly reproducible results.PLoS ONE 01/2010; 5(1):e8893. · 3.73 Impact Factor
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ABSTRACT: Genetic analysis of BRCA1 by sequencing is often preceded by a scanning method like denaturing gradient gel electrophoresis (DGGE), protein truncation test (PTT) or DHPLC. High-resolution melting curve (HRM) analysis is a promising and economical method for high-throughput mutation scanning. The EuroGentest network (www.eurogentest.org) aims to assist with the introduction of novel technologies in the diagnostic setting. Therefore, we have performed a thorough and high-standard interlaboratory evaluation and validation of HRM, in collaboration with Idaho Technology, the manufacturer of the LightScanner (LS). Through this detailed study of 170 variants, we have generated guidelines for easy setup and implementation of HRM as a scanning technique for new genes, which are adaptable to the quality system of an individual diagnostic laboratory. This validation study includes the description of a BRCA1-specific mutation screening test using the 96-well LS. This assay comprises 40 amplicons and was evaluated using a statistically significant elaborate panel of variants and control DNA samples. All heterozygous variants were detected. Moreover, genotype analysis for nine common polymorphisms created a fast screening and detection method for these frequently occurring nonpathogenic variants. A blind study using a total of 28 patient-derived DNA samples resulted also in 100% detection and showed an average specificity of 98%, indicating a low incidence of false positives (FPs).Human Mutation 04/2009; 30(6):899-909. · 5.21 Impact Factor