Method For Detection Of Mutations Research Articles

Validation of a highly sensitive Sanger sequencing in detecting EGFR mutations from circulating tumor DNA in patients with lung cancers

BackgroundThe novel method, named blocker displacement amplification (BDA) Sanger, was applied to detect low variant allele frequency mutations in the circulating tumor DNA (ctDNA). This study aimed to evaluate the performance of the BDA Sanger method for the EGFR mutation detection in the ctDNA from lung cancer patients. MethodsA total of 195 plasma samples of lung cancer patients were included. The EGFR mutation status in the ctDNA was detected by the BDA Sanger and Super-ARMS assays. Next-generation sequencing (NGS) was further used to verify the mutant of EGFR with inconsistencies. ResultsBDA Sanger assay was capable of detecting EGFR mutations with a 0.20% VAF from plasma samples. Among treatment-naive patients with paired tissue and plasma samples, the EGFR positive percent agreement (PPA) was 79% by BDA sanger. EGFR mutation was detected in 34.4% (67/195) ctDNA samples by the Super-ARMS and in 41.0% (80/195) ctDNA samples by the BDA Sanger assay. The overall concordance rate between the BDA Sanger and Super-ARMS assays was 82% (160/195). The BDA Sanger also enabled the detection of rare EGFR mutations, which were not discovered by the Super-ARMS. ConclusionThe results supported the validity and efficiency of the BDA Sanger method for EGFR detection in patients with lung cancer, indicating that BDA Sanger has a great potential for application in detecting mutations in the ctDNA.

Preoperative BRAFV600E mutation detection in thyroid carcinoma by immunocytochemistry.

The BRAFV600E (BRAF) mutation is present in 40-50% of papillary thyroid carcinomas (PTC) and has been associated with more aggressive clinicopathological characteristics of PTC. The aim of this study was to evaluate different methods for preoperative identification of the BRAF mutation in PTC using cytological and histological specimens. Prospectively collected preoperative cytological clots from patients with suspected PTC were tested with BRAF immunocytochemistry (ICC) and the Cobas Test (PCR). In addition, histological specimens were tested with BRAF immunohistochemistry (IHC) and the Cobas Test. All nodules were histologically examined. Fifty-three patients were included in the study. Complete mutation testing was available in 32 patients. The main reason for exclusion was insufficient cell content in the cytological specimen. Twenty-seven nodules were histologically diagnosed as PTC, and 41% (n = 11) of PTCs were BRAF ICC positive. All non-PTC nodules were negative by BRAF ICC. In 26 nodules, all four BRAF tests were concordant, while discordant test results were found in six nodules. ICC was in accordance with the consensus BRAF status in five of these nodules, while BRAF status was undetermined in one nodule. BRAF ICC showed high concordance with the Cobas Test and a low rate of false negative stain. These results indicate that BRAF ICC may be a feasible method for preoperative detection of the BRAFV600E mutation in patients with PTC.

Establishment and application of a method of tagged-amplicon deep sequencing for low-abundance drug resistance in HIV-1

In the latest HIV-1 global drug resistance report released by WHO, countries are advised to strengthen pre-treatment monitoring of drug resistance in AIDS patients. In this study, we established an NGS-based segmented amplification HIV-1 drug resistance mutation detection method. The pol region of HIV-1 was divided into three short fragments for NGS. The entire amplification and sequencing panel were more cost-effective and batched by using the barcode sequence corresponding to the sample. Each parameter was evaluated using samples with known resistance variants frequencies. The nucleotide sequence error rate, amino acid error rate, and noise value of the NGS-based segmented amplification method were both less than 1%. When the threshold was 2%, the consensus sequences of the HIV-1 NL4-3 strain were completely consistent with the Sanger sequences. This method can detect the minimum viral load of the sample at 102 copies/ml, and the input frequency and detection frequency of HIV-1 resistance mutations within the range of 1%–100% had good conformity (R2 = 0.9963; R2 = 0.9955). This method had no non-specific amplification for Hepatitis B and C. Under the 2% threshold, the incidence of surveillance drug resistance mutations in ART-naive HIV-infected patients was 20.69%, among which NRTIs class resistance mutations were mainly.

Detection of NPM1 Mutation in Acute Myeloid Leukemia by Droplet Digital PCR and Its Clinical Application Value

To establish the droplet digital PCR (ddPCR) assay for the detection of NPM1 type A mutation in patients with acute myeloid leukemia (AML), and to evaluate its specificity, sensitivity and its value in clinical application. NPM1 mutant and wildtype plasmids were used to verify the performance of ddPCR. Both ddPCR and Sanger sequencing were used to detect the bone marrow samples of 87 AML patients, which were confirmed by next generation sequencing (NGS). Moreover, NPM1 mutation burden was dynamically monitored in five patients by ddPCR. The limit of blank (LOB) of ddPCR established for NPM1 mutation detection was 1.1 copies/μl, and the limit of detection (LOD) was 2.43 copies/μl, which had good linearity. Among the 87 newly diagnosed AML patients, ddPCR identified seventeen cases positive for NPM1 mutation (19.5%)， which was consistent with Sanger sequencing. NGS confirmed 12 positive cases, including 8 of type A mutations, 2 of type D mutations, and 2 of rare type mutations. The results of dynamic monitoring of NPM1 mutation burden in 5 patients showed that the NPM1 mutation burden decreased obviously even close to 0, when patients achieve complete remission after chemotherapy. However, the mutation burden was increased again at the time of relapse. In this study, we established a ddPCR method for detection of NPM1 mutation with good sensitivity and repeatability, which can be used for screening NPM1 mutation in newly diagnosed AML patients and for minimal residual disease monitoring after remission in positive AML patients to guide treatment.

Evaluation of the ability of Idylla EGFR to differentiate result of ARMS EGFR in gray area and identify rare mutation variants.

e15033 Background: Molecular testing involving Epidermal growth factor receptor ( EGFR) mutations is recommended for patients with non-small cell lung cancer (NSCLC), especially with lung adenocarcinoma, and is nowadays an essential element of precision medicine. Although amplification-refractory mutation system (ARMS) is one of the most commonly used methods for EGFR mutation detection, it can only detect variants in known gene loci and give indistinct results in gray area occasionally, which may be caused by the input of poor DNA quality or low-abundance variants. Idylla EGFR assay can detect 51 EGFR mutations directly from formalin-fixed, paraffin-embedded (FFPE) samples within 2.5 hours with < 2 minutes of hands-on time, without manual data analysis need, whose accurate and robust have been proven among Caucasian and Chinese patients. But the assay’s ability to detect EGFR mutation in low abundance which may lead the result of ARMS EGFR in gray area or rare variants has never been evaluated. Methods: FFPE samples were retrospectively collected from 98 lung cancer patients followed by EGFR testing using the Idylla system, which were also previously assessed with ARMS-PCR. Forty-six of them were in gray area by ARMS-PCR of EGFR and need to be retested by ARMS-PCR or validated by the third method. In another 52 cases, no mutations were found by ARMS-PCR of EGFR, but mutations were found by next-generation sequencing (NGS). The ability of Idylla EGFR to detect cases with result in gray area and rare variants were analyzed. Results: In 46 cases with result in gray area by ARMS-PCR of EGFR, after retesting or validation by the third method, 37 of them had the same result with Idylla mutation test, with an overall concordance of 80.4%. Idylla EGFR test missed 8 mutational cases (22/30), identified 1 mutational case in addition (15/16). Except 2 cases with higher CQ value than 29, which means the poor DNA quality or low quantity input, low mutational abundance maybe the main reason for no mutation identified by Idylla EGFR test. In 52 cases with rare EGFR variants, Idylla EGFR test identified 9 mutational cases, while 4/9 mutational variants beyond the scope of Idylla EGFR test, 2 20ins, 1 L858R and 1 19del. Five of the 9 mutational cases, Idylla test detected 5 different 19dels. The variants of all the 52 cases beyond the scope of ARMS-PCR of EGFR, and ARMS-PCR of EGFR didn’t find mutation. Conclusions: The Idylla system provides a rapid and accurate ability to differentiate result of ARMS-PCR of EGFR in gray area and identify more rare mutation variants which may decrease the repeat testing or validation. But the ability of NGS to find more actionable variants is still important.

BRCA1 and BRCA2 screening of nine Chilean founder mutations through allelic-discrimination and real-time PCR in breast/ovarian cancer patients.

BackgroundIn a previous work, we identified nine founder mutations present in close to 80% of BRCA1 and BRCA2 mutation carriers, and distributed across the country. The presence of founder mutations constitutes a valuable opportunity to develop new strategies for genetic screening. Genetic tests are primarily performed by NGS sequencing, which requires sophisticated and expensive equipment, and it takes 2–3 weeks for the results to be informed to the patient. In addition, genetic tests are not covered by insurance companies in Latin American countries. In this work, we present the standardization and technical validation of a real-time PCR based methodology for allelic discrimination in order to identify the nine Chilean founder mutations in BRCA1 and BRCA2 genes.Methods and resultsWe designed nine pairs of probes and nine pairs of primers to amplify synchronically nine regions of the BRCA1/BRCA2 genes by real-time PCR, in order to identify the nine founder mutations through allelic discrimination analyses. Technical validation was performed using 90 positive and 90 negative samples for each mutation. The methodology was tested in a second group of 60 patients. Our method correctly classified carriers and non-carriers of one of the nine Chilean founder mutations with a 100% specificity and 100% sensitivity, compared with Sanger sequencing performance.ConclusionsWe develop an inexpensive, simple, and fast mutation detection method that could be implemented locally in Hospitals from the Private to Public health system. This methodology may be useful for the screening of BRCA1 and BRCA2 mutations in other populations.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11033-022-07561-4.

A custom ddPCR method for the detection of copy number variations in the nebulin triplicate region.

The human genome contains repetitive regions, such as segmental duplications, known to be prone to copy number variation. Segmental duplications are highly identical and homologous sequences, posing a specific challenge for most mutation detection methods. The giant nebulin gene is expressed in skeletal muscle. It harbors a large segmental duplication region composed of eight exons repeated three times, the so-called triplicate region. Mutations in nebulin are known to cause nemaline myopathy and other congenital myopathies. Using our custom targeted Comparative Genomic Hybridization arrays, we have previously shown that copy number variations in the nebulin triplicate region are pathogenic when the copy number of the segmental duplication block deviates two or more copies from the normal number, which is three per allele. To complement our Comparative Genomic Hybridization arrays, we have established a custom Droplet Digital PCR method for the detection of copy number variations within the nebulin triplicate region. The custom Droplet Digital PCR assays allow sensitive, rapid, high-throughput, and cost-effective detection of copy number variations within this region and is ready for implementation a screening method for disease-causing copy number variations of the nebulin triplicate region. We suggest that Droplet Digital PCR may also be used in the study and diagnostics of other segmental duplication regions of the genome.

Method for the Intraoperative Detection of IDH Mutation in Gliomas with Differential Mobility Spectrometry.

Isocitrate dehydrogenase (IDH) mutation status is an important factor for surgical decision-making: patients with IDH-mutated tumors are more likely to have a good long-term prognosis, and thus favor aggressive resection with more survival benefit to gain. Patients with IDH wild-type tumors have generally poorer prognosis and, therefore, conservative resection to avoid neurological deficit is favored. Current histopathological analysis with frozen sections is unable to identify IDH mutation status intraoperatively, and more advanced methods are therefore needed. We examined a novel method suitable for intraoperative IDH mutation identification that is based on the differential mobility spectrometry (DMS) analysis of the tumor. We prospectively obtained tumor samples from 22 patients, including 11 IDH-mutated and 11 IDH wild-type tumors. The tumors were cut in 88 smaller specimens that were analyzed with DMS. With a linear discriminant analysis (LDA) algorithm, the DMS was able to classify tumor samples with 86% classification accuracy, 86% sensitivity, and 85% specificity. Our results show that DMS is able to differentiate IDH-mutated and IDH wild-type tumors with good accuracy in a setting suitable for intraoperative use, which makes it a promising novel solution for neurosurgical practice.

A Complex of Pyrosequencing-Based Methods for Detection of Somatic Mutations in Codons 600 and 601 of the BRAF gene.

The nucleotide sequence of the BRAF codons 592-602 was identified using the PyroMark Q24 genetic analysis system. The mutations search in codon 600 was conducted using the 600-S primer in line with the following order of adding nucleotides: GCTGTCАTCTGCTAGCTAGAC (corresponding to nucleotides 1799-1786). The K601E mutation was detected using the 601-S primer in line with the following order of nucleotide addition: GCTACTCACTGTAG (corresponding to nucleotides 1801-1793). The analytical characteristics of the proposed methods for somatic mutations' detection were determined using dilutions of plasmid DNA samples containing the BRAF gene region without mutations or with one of the following mutations: V600E, V600R, V600K, V600M, and K601E. Validation was performed on 132 samples of biological material obtained from the thyroid nodules. The developed methods allow to determine 2% of the V600E or V600M mutations, 1% of the V600K and V600R mutations, and 3% of the K601E mutations in samples with high DNA concentration; it is also possible to confidently detect at least 5% of the mutant allele for all mutations in low concentration samples (less than 500 copies/PCR). During biological material testing, 53 samples with the V600E mutation were detected; the proportion of the mutant allele was 4.9-50.0%. A complex of methods for determination of the nucleotide sequence of the BRAF codons 592-601 and the algorithm for testing samples and analyzing mutations in the BRAF codons 600-601 was developed. The method provides sufficient sensitivity to detect frequent mutations in codons 600 and 601 and allows them to be precisely differentiated.

Novel hybridization- and tag-based error-corrected method for sensitive ctDNA mutation detection using ion semiconductor sequencing

Circulating tumor DNA (ctDNA) analysis has emerged as a clinically useful tool for cancer diagnostics and treatment monitoring. However, ctDNA detection is complicated by low DNA concentrations and technical challenges. Here we describe our newly developed sensitive method for ctDNA detection on the Ion Torrent sequencing platform, which we call HYbridization- and Tag-based Error-Corrected sequencing (HYTEC-seq). This method combines hybridization-based capture with molecular tags, and the novel variant caller PlasmaMutationDetector2 to eliminate background errors. We describe the validation of HYTEC-seq using control samples with known mutations, demonstrating an analytical sensitivity down to 0.1% at > 99.99% specificity. Furthermore, to demonstrate the utility of this method in a clinical setting, we analyzed plasma samples from 44 patients with advanced pancreatic cancer, revealing mutations in 57% of the patients at allele frequencies as low as 0.23%.

Nano2NGS-Muta: a framework for converting nanopore sequencing data to NGS-liked sequencing data for hotspot mutation detection.

Nanopore sequencing, also known as single-molecule real-time sequencing, is a third/fourth generation sequencing technology that enables deciphering single DNA/RNA molecules without the polymerase chain reaction. Although nanopore sequencing has made significant progress in scientific research and clinical practice, its application has been limited compared with next-generation sequencing (NGS) due to specific design principle and data characteristics, especially in hotspot mutation detection. Therefore, we developed Nano2NGS-Muta as a data analysis framework for hotspot mutation detection based on long reads from nanopore sequencing. Nano2NGS-Muta is characterized by applying nanopore sequencing data to NGS-liked data analysis pipelines. Long reads can be converted into short reads and then processed through existing NGS analysis pipelines in combination with statistical methods for hotspot mutation detection. Nano2NGS-Muta not only effectively avoids false positive/negative results caused by non-random errors and unexpected insertions-deletions (indels) of nanopore sequencing data, improves the detection accuracy of hotspot mutations compared to conventional nanopore sequencing data analysis algorithms but also breaks the barriers of data analysis methods between short-read sequencing and long-read sequencing. We hope Nano2NGS-Muta can serves as a reference method for nanopore sequencing data and promotes higher application scope of nanopore sequencing technology in scientific research and clinical practice.

Simultaneous detection of SARS-CoV-2 and identification of spike D614G mutation using point-of-care real-time polymerase chain reaction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with high mortality and infectivity rates in humans since its emergence. Analysis using high-accuracy real-time polymerase chain reaction (PCR) is recommended for the detection of general respiratory viruses including SARS-CoV-2, but it takes a long time (e.g. ~ 6 h); moreover, on-site diagnosis is difficult owing to the need for skilled technicians and advanced laboratory facilities. Currently, the importance of point-of-care testing (POCT) is being emphasized for the rapid detection of SARS-CoV-2. Here, we developed a multiplex real-time reverse transcription PCR (rRT-PCR) analysis that not only detects SARS-CoV-2 but also D614G strains with higher contagiousness than wild types among SARS-CoV-2 mutants using probe-based rRT-PCR. Moreover, this method was applied to portable PCR equipment capable of POCT to confirm high detection sensitivity and specificity. Multiple assays were possible with fluorescence labeling of individual probes. Furthermore, using a microfluidic chip-based point-of-care testing rRT-PCR platform, detection time was reduced by more than half compared with the commonly used detection system. This demonstrates that our assay has 100% of high sensitivity and specificity and could thus aid in the rapid and simple screening of SARS-CoV-2 carrying the mutation. We present a rapid detection method for mutations in SARS-CoV-2.

SmMIP-tools: a computational toolset for processing and analysis of single-molecule molecular inversion probes-derived data.

MotivationSingle-molecule molecular inversion probes (smMIPs) provide an exceptionally cost-effective and modular approach for routine or large-cohort next-generation sequencing. However, processing the derived raw data to generate highly accurate variants calls remains challenging.ResultsWe introduce SmMIP-tools, a comprehensive computational method that promotes the detection of single nucleotide variants and short insertions and deletions from smMIP-based sequencing. Our approach delivered near-perfect performance when benchmarked against a set of known mutations in controlled experiments involving DNA dilutions and outperformed other commonly used computational methods for mutation detection. Comparison against clinically approved diagnostic testing of leukaemia patients demonstrated the ability to detect both previously reported variants and a set of pathogenic mutations that did not pass detection by clinical testing. Collectively, our results indicate that increased performance can be achieved when tailoring data processing and analysis to its related technology. The feasibility of using our method in research and clinical settings to benefit from low-cost smMIP technology is demonstrated.Availability and implementationThe source code for SmMIP-tools, its manual and additional scripts aimed to foster large-scale data processing and analysis are all available on github (https://github.com/abelson-lab/smMIP-tools). Raw sequencing data generated in this study have been submitted to the European Genome-Phenome Archive (EGA; https://ega-archive.org) and can be accessed under accession number EGAS00001005359.Supplementary information Supplementary data are available at Bioinformatics online.

HRM method for identification of TP53 exon 5 and 8 mutations in human prostate cancer patients

BackgroundThe purpose of the present study was to perform a high-resolution melting (HRM) analysis to discover mutations in gene exons 5–8 of tumor protein p53 (TP53), as well as the relationships of these mutations to clinical parameters in prostate cancer (PC). MethodsGenomic DNA was extracted from 50 formalin-fixed paraffin-embedded (FFPE) tissues with PC. Mutations in exons 5 and 8 of TP53 were analyzed using the HRM method. Sanger sequencing was used to describe mutations. ResultsAccording to the HRM analysis results, 21 (42%) PC samples had different normalized and shifted melting curves from other samples. Mutations in TP53 exons 5 and8 were observed in 12 (24%) patients by the Sanger method. The detection sensitivity of the HRM method in exon 5 and exon 8 mutations was 66.7% and 50%, respectively. PSA levels of PC patients with TP53 mutation were found to be lower than that of patients with no mutation (p = 0.8270). However, we did not find any correlations between TP53 mutations and clinical parameters (p > 0.05). ConclusionsHRM analysis is a simple, rapid, and efficient mutation-scanning method for known/unknown mutations in TP53 exons 5and8, as well as an attractive method for detection of mutations and their analysis in FFPE tissues. Additional studies with larger patient populations are warranted to confirm the correlation between the TP53 mutations and PC risk.

Frequency of Nucleophosmin 1 Expression by Immunohistochemistry in Acute Myeloid Leukemia.

Nucleophosmin (NPM1) mutation is one of the most common recurring genetic abnormalities seen in acute myeloid leukemia (AML). Immunohistochemistry serves as a cost effective and simple surrogate testing method for detection of NPM1 mutation. This study was conducted to evaluate the frequency of aberrant cytoplasmic nucleophosmin 1 expression in leukemic blast cells on formalin fixed bone marrow trephine biopsy (BMB) sections and also to correlate this data with the reference molecular method (reverse transcriptase-polymerase chain reaction; RT-PCR and gene sequencing), where available. Immunostains were performed using mouse anti-NPM1 monoclonal antibody on 71 paraffin embedded bone marrow biopsies (BMB) of patients with AML of any French-American-British (FAB) subtype. Results of immunohistochemistry (IHC) were then compared with the reference molecular method. The proportion of NPM1 expression by immunostaining in AML cases was found to be 17%. Twelve of the total 71 cases demonstrated cytoplasmic nucleophosmin (NPMc+) on immunostaining. Eleven of the positive cases that were correlated with the molecular standard demonstrated mutation in exon 12 of NPM1 gene. Cytoplasmic nucleophosmin expression by immunostaining was found to be in complete agreement with the standard molecular method. In a resource restricted setup, the information from this study might help in providing an inexpensive and accurate detection method to facilitate introduction of this marker in diagnostic and prognostic workup of AML especially in patients showing normal karyotype and no common recurrent translocations.

Evaluation of molecular methods for plasma detection of EGFR mutations in non-small cell lung cancer.

Epidermal growth factor receptor (EGFR) mutations are detected in non-small cell lung cancer (NSCLC) and associated with responses to therapy with tyrosine kinase inhibitors (TKIs). We compared the analytical performances of two real-time PCRs and droplet digital PCR (ddPCR) to detect EGFR mutations using plasma. Plasma EGFR tests were performed using 86 plasma samples from 75 prospectively enrolled NSCLC patients with early and advanced stages. Analytical performances of plasma-using two real-time PCR, Cobas EGFR mutation v2 and PANAMutyper, EGFR kit, and ddPCR were evaluated based on the tissue EGFR test results. The frequencies of EGFR mutations and acquired T790M mutation after TKI therapy were also assessed. The incidence of all EGFR mutations was 52.3% (23/44) in tissue and was up to 43.2% (19/44) in plasma. The Cobas detection rates of three EGFR mutations (exon 19 deletions, L858R, and T790M) in plasma were similar to those in tissue. The Cobas showed a higher detection rate (76.7%) than that by the PANAMutyper (60.5%). Sensitivity for T790M mutation was lower than the sensitivity for the exon 19 deletions or L858R in both tests. Mutant allele frequency measured by ddPCR was significantly correlated with the semi-quantitative values of the Cobas. Plasma EGFR tests showed similar detection rates for common EGFR mutations compared to the tissue EGFR tests. Cobas showed higher sensitivity in detection of EGFR mutations in body fluids than the PANAMutyper. Real-time PCR using plasma or body fluids could be a suitable first test for the detection of EGFR mutations.

Endonuclease IV-mediated substrate structure allosteric for universal and sensitive mutant allele enrichment and discrimination

In this work, the structure allosteric induced by Endonuclease IV (Endo IV) preference to the specific substrate was ingeniously combined with the asymmetric PCR technique. As a result, it could construct a universal and straightforward strategy for mutant allele enrichment (IVME) to improve the sensitivity of downstream mutation detection methods. At the initial time, both the mutant-type target (MT) and the wild-type target (WT) would hybridize with the probe (FP) containing apurinic/apyrimidinic site to form a flap structure, which could not be used to perform asymmetric PCR. Once Endo IV was added, the substrate formed by FP and MT, not the FP-WT, could be recognized and cleaved due to the high single nucleotide discrimination ability of Endo IV. Subsequently, the flap structure at the 3′ terminal was destroyed and exposed an active 3′-OH, which could act as a primer in the asymmetric PCR. Thus, both the absolute amount and the abundance of MT were enhanced. 1% and 0.01% MT could be directly distinguished by coupling with Sanger sequencing and Endo IV-assisted nucleic probe hybridization-based DNA mutation detection method, respectively. EGFR T790M mutation in the peripheral blood of a non-small cell lung cancer patient was detected by IVME coupled with Sanger sequence. The results were also verified by next-generation sequencing, which demonstrated the potential clinical application of our proposed strategy.

Rapid detection of FLT3-ITD (exon14-15) gene mutations analysis in acute myelogenous leukemia patients by High Resolution Melting analysis

Background: Molecular genetic characterization allows prognostic stratification and can potentially alter treatment choices in acute myeloid leukemia (AML). Activating mutations of the Fsm-like tyrosine kinase3 (FLT3) gene, especially FLT3-ITD mutations, have been associated with an adverse prognosis in AML. Therefore, FLT3 mutation detection becomes essential for AML patients. High Resolution Melting (HRM) analysis is an alternative method for the rapid and affordable detection of gene mutations. Objectives:To establish and evaluate a rapid and affordable method for detecting mutations of FLT3-ITD (exon14-15) gene in acute myeloid leukemia by High Resolution Melting analysis. Materials and Methods: Thirty-five patients with newly diagnosed AML from Maharaj Nakorn Chiang Mai Hospital were included in this study. FLT3-ITD mutation screening was performed by HRM analysis, and the results were compared with the data obtained using conventional PCR with gel electrophoresis and direct sequencing. Results: Among the 35 AML patients studied, 6 patients were scored positively for FLT3-ITD mutation in the conventional PCR, whereas HRM analysis identified 7 out of 35 patients who were positive for FLT3-ITD mutation, which was concordant with direct sequencing results. Interestingly, one sample that was positive by HRM analysis was scored by conventional PCR as negative. Therefore, HRM analysis is more sensitive than conventional PCR. Conclusion: HRM analysis is a rapid and promising screening method for FLT3-ITD mutation, enabling the real-time evaluation of AML progression, which is significant for decision-making regarding treatment. Our results showed that HRM analysis could be a useful clinical tool for the rapid and affordable screening of FLT3-ITD mutation in AML patients.

A family screening of CD19 gene mutation by PCR-RFLP

Introduction and aim. Mutation(s) in the gene encoding the CD19 molecule affect CD19 protein expression and primary immunodeficiency (PID) occurs. The PCR-RFLP method, which is faster and cheaper than other mutation detection methods, is rarely used in the diagnosis of PID. The study aimed to genetically identify CD19 deficiency, which is a PID, using the PCR-RFLP method. Material and methods. A total of 8 patients and two healthy controls were included in the study and the relevant region genotypes in the CD19 gene were determined by performing PCR-RFLP analysis. Results. The index case, newborn baby and mother were also included in the study. It was determined that the index case (P6) was homozygous mutant, the newborn baby (P7) and mother (P8) had heterozygous genotype. Based on this situation, one child (P1) was found to be homozygous mutant, mother (P2), father (P3) and other children (P4 and P5) had heterozygous genotype in the family, which was determined to be related to the first case. Conclusion. In our study, it has been shown that PCR-RFLP is a method that can be used in the diagnosis of PID by determining genotypes using PCR-RFLP, and especially in terms of rapid genetic testing of family screenings.

Enzyme-Free Colorimetric Method for Fast Detection of Pik3ca Gene Mutation by Praseodymia Nanorods

Enzyme-Free Colorimetric Method for Fast Detection of Pik3ca Gene Mutation by Praseodymia Nanorods