• Title/Summary/Keyword: Mutant allele burden

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Fragment Analysis for Detection of the FLT3-Internal Tandem Duplication: Comparison with Conventional PCR and Sanger Sequencing (FLT3-ITD 검출을 위한 절편분석법: 일반 중합효소연쇄반응 및 직접염기서열분석법과의 비교)

  • Lee, GunDong;Kim, Jeongeun;Lee, SangYoon;Jang, Woori;Park, Joonhong;Chae, Hyojin;Kim, Myungshin;Kim, Yonggoo
    • Laboratory Medicine Online
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    • v.7 no.1
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    • pp.13-19
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    • 2017
  • Background: We evaluated a sensitive and quantitative method utilizing fragment analysis of the fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD), simultaneously measuring mutant allele burden and length, and verified the analytical performance. Methods: The number and allelic burden of FLT3-ITD mutations was determined by fragment analysis. Serial mixtures of mutant and wild-type plasmid DNA were used to calculate the limit of detection of fragment analysis, conventional PCR, and Sanger sequencing. Specificity was evaluated using DNA samples derived from 50 normal donors. Results of fragment analysis were compared to those of conventional PCR, using 481 AML specimens. Results: Defined mixtures were consistently and accurately identified by fragment analysis at a 5% relative concentration of mutant to wild-type, and at 10% and 20% ratios by conventional PCR and direct sequencing, respectively. No false positivity was identified. Among 481 AML specimens, 40.1% (193/481) had FLT3-ITD mutations. The mutant allele burden (1.7-94.1%; median, 28.2%) and repeated length of the mutation (14-153 bp; median, 49 bp) were variable. The concordance rate between fragment analysis and conventional PCR was 97.7% (470/481). Fragment analysis was more sensitive than conventional PCR and detected 11 additional cases: seven had mutations below 10%, three cases represented conventional PCR failure, and one case showed false negativity because of short ITD length (14 bp). Conclusions: The new fragment analysis method proved to be sensitive and reliable for the detection and monitoring of FLT3-ITD in patients with AML. This could be used to simultaneously assess ITD mutant allele burden and length.

Characterization and Prognosis Significance of JAK2 (V617F), MPL, and CALR Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

  • Singdong, Roongrudee;Siriboonpiputtana, Teerapong;Chareonsirisuthigul, Takol;Kongruang, Adcharee;Limsuwanachot, Nittaya;Sirirat, Tanasan;Chuncharunee, Suporn;Rerkamnuaychoke, Budsaba
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.10
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    • pp.4647-4653
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    • 2016
  • Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical presentation, disease progression, and treatment outcome. Material and Methods: Pyrosequencing was performed to detect JAK2 (V617F) and MPL (W515K/L) and capillary electrophoresis to identify CALR exon 9 mutations in 100 samples of Ph-negative MPNs (38.0 PV, 55 ET, 4 PMF, and 3 MPN-U). Results: The results showed somatic mutations of JAK2 (V617F) in 94.7% of PV, 74.5% of ET, 25.0% of PMF, and all MPN-U. A high proportion of JAK2 (V617F) mutant allele burden (mutational load > 50.0%) was predominantly observed in PV when compared with ET. Although a high level of JAK2 (V617F) allele burden was strongly associated with high WBC counts in both PV and ET, several hematological parameters (hemoglobin, hematocrit, and platelet count) were independent of JAK2 (V617F) mutational load. MPL (W515K/L) mutations could not be detected whereas CALR exon 9 mutations were identified in 35.7% of patients with JAK2 negative ET and 33.3% with JAK2 negative PMF. Conclusions: The JAK2 (V617F) allele burden may be involved in progression of MPNs. Furthermore, a high level of JAK2 (V617F) mutant allele appears strongly associated with leukocytosis in both PV and ET.

Associations between single-nucleotide polymorphisms of the interleukin-18 gene and breast cancer in Iraqi women

  • Zakariya, Bilal Fadil;Almohaidi, Asmaa M. Salih;Simsek, Secil Akilli;Kamal, Areege Mustafa;Al-Dabbagh, Wijdan H.;Al-Waysi, Safaa A.
    • Genomics & Informatics
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    • v.20 no.2
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    • pp.18.1-18.7
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    • 2022
  • According to long-term projections, by 2030, the world's population is predicted to reach 7.5 billion individuals, and there will be roughly 27 million new cancer cases diagnosed. The global burden of breast cancer (BC) is expected to rise. According to the Ministry of Health-Iraqi Cancer Registry, cancer is the second largest cause of death after cardiovascular disease. This study investigated the interleukin-18 (IL18) single-nucleotide polymorphisms (SNPs) -607C/A rs1946518 and -137G/C rs187238 using the sequence-specific amplification-polymerase chain reaction approach. Regarding the position -607C/A, there was a highly significant difference between the observed and expected frequencies in patients and controls (χ2 = 3.16 and χ2 = 16.5), respectively. The AA and CA genotypes were associated with significantly increased BC risk (odds ratio [OR], 3.68; p = 0.004 and OR, 2.83; p = 0.04, respectively). Women with the A allele had a 5.03-fold increased susceptibility to BC. The C allele may be a protective allele against BC (OR, 0.19). Although position -137G/C showed no significant differences in the CC genotype distribution (p = 0.18), the frequency of the CC genotype was significantly higher in patients than in controls. In contrast, patients had a significantly higher frequency of GC genotypes than controls (p = 0.04), which was associated with an increased risk of developing BC (OR, 2.63). The G allele frequency was significantly lower in patients than in controls (55.0% vs. 76.2%, respectively). This SNP may be considered a common genotype in the Iraqi population, with the wild-type G allele having a protective function (OR, 0.19) and the mutant C allele having an environmental effect (OR, 2.63).