scholarly journals Proficiency Testing of Standardized Samples Shows High Interlaboratory Agreement for Clinical Next-Generation Sequencing–Based Hematologic Malignancy Assays With Survey Material–Specific Differences in Variant Frequencies

2020 ◽  
Vol 144 (8) ◽  
pp. 959-966 ◽  
Author(s):  
Alissa Keegan ◽  
Julia A. Bridge ◽  
Neal I. Lindeman ◽  
Thomas A. Long ◽  
Jason D. Merker ◽  
...  

Context.— As laboratories increasingly turn from single-analyte testing in hematologic malignancies to next-generation sequencing–based panel testing, there is a corresponding need for proficiency testing to ensure adequate performance of these next-generation sequencing assays for optimal patient care. Objective.— To report the performance of laboratories on proficiency testing from the first 4 College of American Pathologists Next-Generation Sequencing Hematologic Malignancy surveys. Design.— College of American Pathologists proficiency testing results for 36 different engineered variants and/or allele fractions as well as a sample with no pathogenic variants were analyzed for accuracy and associated assay performance characteristics. Results.— The overall sensitivity observed for all variants was 93.5% (2190 of 2341) with 99.8% specificity (22 800 of 22 840). The false-negative rate was 6.5% (151 of 2341), and the largest single cause of these errors was difficulty in identifying variants in the sequence of CEBPA that is rich in cytosines and guanines. False-positive results (0.18%; 40 of 22 840) were most likely the result of preanalytic or postanalytic errors. Interestingly, the variant allele fractions were almost uniformly lower than the engineered fraction (as measured by digital polymerase chain reaction). Extensive troubleshooting identified a multifactorial cause for the low variant allele fractions, a result of an interaction between the linearized nature of the plasmid and the Illumina TruSeq chemistry. Conclusions.— Laboratories demonstrated an overall accuracy of 99.2% (24 990 of 25 181) with 99.8% specificity and 93.5% sensitivity when examining 36 clinically relevant somatic single-nucleotide variants with a variant allele fraction of 10% or greater. The data also highlight an issue with artificial linearized plasmids as survey material for next-generation sequencing.

2018 ◽  
Vol 143 (4) ◽  
pp. 463-471 ◽  
Author(s):  
Jason D. Merker ◽  
Kelly Devereaux ◽  
A. John Iafrate ◽  
Suzanne Kamel-Reid ◽  
Annette S. Kim ◽  
...  

Context.— Next-generation sequencing–based assays are being increasingly used in the clinical setting for the detection of somatic variants in solid tumors, but limited data are available regarding the interlaboratory performance of these assays. Objective.— To examine proficiency testing data from the initial College of American Pathologists (CAP) Next-Generation Sequencing Solid Tumor survey to report on laboratory performance. Design.— CAP proficiency testing results from 111 laboratories were analyzed for accuracy and associated assay performance characteristics. Results.— The overall accuracy observed for all variants was 98.3%. Rare false-negative results could not be attributed to sequencing platform, selection method, or other assay characteristics. The median and average of the variant allele fractions reported by the laboratories were within 10% of those orthogonally determined by digital polymerase chain reaction for each variant. The median coverage reported at the variant sites ranged from 1922 to 3297. Conclusions.— Laboratories demonstrated an overall accuracy of greater than 98% with high specificity when examining 10 clinically relevant somatic single-nucleotide variants with a variant allele fraction of 15% or greater. These initial data suggest excellent performance, but further ongoing studies are needed to evaluate the performance of lower variant allele fractions and additional variant types.


2016 ◽  
Vol 140 (10) ◽  
pp. 1085-1091 ◽  
Author(s):  
Eric J. Duncavage ◽  
Haley J. Abel ◽  
Jason D. Merker ◽  
John B. Bodner ◽  
Qin Zhao ◽  
...  

Context.—Most current proficiency testing challenges for next-generation sequencing assays are methods-based proficiency testing surveys that use DNA from characterized reference samples to test both the wet-bench and bioinformatics/dry-bench aspects of the tests. Methods-based proficiency testing surveys are limited by the number and types of mutations that either are naturally present or can be introduced into a single DNA sample. Objective.—To address these limitations by exploring a model of in silico proficiency testing in which sequence data from a single well-characterized specimen are manipulated electronically. Design.—DNA from the College of American Pathologists reference genome was enriched using the Illumina TruSeq and Life Technologies AmpliSeq panels and sequenced on the MiSeq and Ion Torrent platforms, respectively. The resulting data were mutagenized in silico and 26 variants, including single-nucleotide variants, deletions, and dinucleotide substitutions, were added at variant allele fractions (VAFs) from 10% to 50%. Participating clinical laboratories downloaded these files and analyzed them using their clinical bioinformatics pipelines. Results.—Laboratories using the AmpliSeq/Ion Torrent and/or the TruSeq/MiSeq participated in the 2 surveys. On average, laboratories identified 24.6 of 26 variants (95%) overall and 21.4 of 22 variants (97%) with VAFs greater than 15%. No false-positive calls were reported. The most frequently missed variants were single-nucleotide variants with VAFs less than 15%. Across both challenges, reported VAF concordance was excellent, with less than 1% median absolute difference between the simulated VAF and mean reported VAF. Conclusions.—The results indicate that in silico proficiency testing is a feasible approach for methods-based proficiency testing, and demonstrate that the sensitivity and specificity of current next-generation sequencing bioinformatics across clinical laboratories are high.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Michael M. Khayat ◽  
Sayed Mohammad Ebrahim Sahraeian ◽  
Samantha Zarate ◽  
Andrew Carroll ◽  
Huixiao Hong ◽  
...  

Abstract Background Genomic structural variations (SV) are important determinants of genotypic and phenotypic changes in many organisms. However, the detection of SV from next-generation sequencing data remains challenging. Results In this study, DNA from a Chinese family quartet is sequenced at three different sequencing centers in triplicate. A total of 288 derivative data sets are generated utilizing different analysis pipelines and compared to identify sources of analytical variability. Mapping methods provide the major contribution to variability, followed by sequencing centers and replicates. Interestingly, SV supported by only one center or replicate often represent true positives with 47.02% and 45.44% overlapping the long-read SV call set, respectively. This is consistent with an overall higher false negative rate for SV calling in centers and replicates compared to mappers (15.72%). Finally, we observe that the SV calling variability also persists in a genotyping approach, indicating the impact of the underlying sequencing and preparation approaches. Conclusions This study provides the first detailed insights into the sources of variability in SV identification from next-generation sequencing and highlights remaining challenges in SV calling for large cohorts. We further give recommendations on how to reduce SV calling variability and the choice of alignment methodology.


Author(s):  
Valentina Nardi ◽  
Karen D. Tsuchiya ◽  
Annette S. Kim ◽  
Lora J. H. Bean ◽  
Jaimie G. Halley ◽  
...  

Context.— Next-generation sequencing–based assays are increasingly used in clinical molecular laboratories to detect somatic variants in solid tumors and hematologic malignancies and to detect constitutional variants. Proficiency testing data are potential sources of information about challenges in performing these assays. Objective.— To examine the most common sources of unacceptable results from the College of American Pathologists Next-Generation Sequencing Bioinformatics, Hematological Malignancies, Solid Tumor, and Germline surveys, and provide recommendations on how to avoid these pitfalls and improve performance. Design.— The College of American Pathologists next-generation sequencing somatic and germline proficiency testing survey results from 2016 to 2019 were analyzed to identify the most common causes of unacceptable results. Results.— On somatic and germline proficiency testing surveys, 95.9% (18 815/19 623) and 97.8% (33 890/34 641) of all variants were correctly identified, respectively. The most common causes of unacceptable results related to sequencing were false-negative errors in genomic regions that were difficult to sequence because of high GC content. False-positive errors occurred in the context of homopolymers and pseudogenes. Recurrent errors in variant annotation were seen for dinucleotide and duplication variants and included unacceptable transcript selection and outdated variant nomenclature. A small percentage of preanalytic or postanalytic errors were attributed to specimen swaps and transcription errors. Conclusions.— Laboratories demonstrate overall excellent performance for detecting variants in both somatic and germline proficiency testing surveys. Proficiency testing survey results highlight infrequent, but recurrent, analytic and nonanalytic challenges in performing next- generation sequencing–based assays and point to remedies to help laboratories improve performance.


2021 ◽  
Author(s):  
Xin-Qi Teng ◽  
Wen-Cheng Gong ◽  
Ting-Ting Qi ◽  
Guo-Hua Li ◽  
Qiang Qu ◽  
...  

Abstract Introduction: Chlamydia psittaci infection is a zoonotic infectious disease, which mainly inhaled through the lungs when exposed to the secretions of poultry that carry pathogenic bacteria. The traditional respiratory specimens or serological antibody testing is slow and the false-negative rate is high. Metagenomic next-generation sequencing gives a promising rapid diagnosis tool. Methods: We retrospective summarized the clinical characteristics of five C. psittaci pneumonia patients diagnosed by mNGS, conducted a literature review summarizing the clinical characteristics of patients with C. psittaci pneumonia reported since 2010.Results: Five C. psittaci. pneumonia patients confirmed by mNGS aged from 36 to 66 years with three males. 60% of patients had type 2 diabetes mellitus. And 60% of patients had a history of contact with avian or poultry. All patients had a high fever over 38.5 °C, cough, hypodynamia, hypoxemia, and dyspnea on admission. Two patients had invasive ventilator support and Extracorporeal Membrane Oxygenation support. The levels of C-reactive protein, procalcitonin, and erythrocyte sedimentation rate on admission and follow-up were all higher than normal values. Doxycycline or moxifloxacin monotherapy was accounted for 1/5 (20%) and 2/5 (40%) patients, and combination therapy was accounted for 2/5(40%) patients. Four patients improved and were discharged, and one patient died due to multiple organ failure and disseminated intravascular coagulation.Conclusions: mNGS can increase the detection rate of C. psittaci, shorten the diagnosis time of C. psittaci pneumonia and improve the prognosis of patients.


Author(s):  
Bing M. Zhang ◽  
Alissa Keegan ◽  
Peng Li ◽  
Neal I. Lindeman ◽  
Rakesh Nagarajan ◽  
...  

Context.— With the increasing integration of molecular alterations into the evaluation of hematologic malignancies (HM), somatic mutation profiling by next-generation sequencing (NGS) has become a common clinical testing strategy. Limited data are available about the characteristics of these assays. Objective.— To describe assay characteristics, specimen requirements, and reporting practices for NGS-based HM testing using College of American Pathologists proficiency testing survey data. Design.— The College of American Pathologists NGS Hematologic Malignancies Survey (NGSHM) results from 78 laboratories were used to determine laboratory practices in NGS-based HM testing. Results.— The majority of laboratories performed tumor-only (88.5% [69 of 78]), targeted sequencing of cancer genes or mutation hotspots (98.7% [77 of 78]); greater than 90% performed testing on fresh bone marrow and peripheral blood. The majority of laboratories reported a 5% lower limit of detection for single-nucleotide variants (73.1% [57 of 78]) and small insertions and deletions (50.6% [39 of 77]). A majority of laboratories used benchtop sequencers and custom enrichment approaches. Conclusions.— This manuscript summarizes the characteristics of clinical NGS-based testing for the detection of somatic variants in HM. These data may be broadly useful to inform laboratory practice and quality management systems, regulation, and oversight of NGS testing, and precision medicine efforts using a data-driven approach.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Nika Maani ◽  
Karen Panabaker ◽  
Jeanna M. McCuaig ◽  
Kathleen Buckley ◽  
Kara Semotiuk ◽  
...  

AbstractNext-generation sequencing (NGS) technologies have facilitated multi-gene panel (MGP) testing to detect germline DNA variants in hereditary cancer patients. This sensitive technique can uncover unexpected, non-germline incidental findings indicative of mosaicism, clonal hematopoiesis (CH), or hematologic malignancies. A retrospective chart review was conducted to identify cases of incidental findings from NGS-MGP testing. Inclusion criteria included: 1) multiple pathogenic variants in the same patient; 2) pathogenic variants at a low allele fraction; and/or 3) the presence of pathogenic variants not consistent with family history. Secondary tissue analysis, complete blood count (CBC) and medical record review were conducted to further delineate the etiology of the pathogenic variants. Of 6060 NGS-MGP tests, 24 cases fulfilling our inclusion criteria were identified. Pathogenic variants were detected in TP53, ATM, CHEK2, BRCA1 and APC. 18/24 (75.0%) patients were classified as CH, 3/24 (12.5%) as mosaic, 2/24 (8.3%) related to a hematologic malignancy, and 1/24 (4.2%) as true germline. We describe a case-specific workflow to identify and interpret the nature of incidental findings on NGS-MGP. This workflow will provide oncology and genetic clinics a practical guide for the management and counselling of patients with unexpected NGS-MGP findings.


2017 ◽  
Vol 141 (12) ◽  
pp. 1679-1685 ◽  
Author(s):  
Rakesh Nagarajan ◽  
Angela N. Bartley ◽  
Julia A. Bridge ◽  
Lawrence J. Jennings ◽  
Suzanne Kamel-Reid ◽  
...  

Context.— Detection of acquired variants in cancer is a paradigm of precision medicine, yet little has been reported about clinical laboratory practices across a broad range of laboratories. Objective.— To use College of American Pathologists proficiency testing survey results to report on the results from surveys on next-generation sequencing–based oncology testing practices. Design.— College of American Pathologists proficiency testing survey results from more than 250 laboratories currently performing molecular oncology testing were used to determine laboratory trends in next-generation sequencing–based oncology testing. Results.— These presented data provide key information about the number of laboratories that currently offer or are planning to offer next-generation sequencing–based oncology testing. Furthermore, we present data from 60 laboratories performing next-generation sequencing–based oncology testing regarding specimen requirements and assay characteristics. The findings indicate that most laboratories are performing tumor-only targeted sequencing to detect single-nucleotide variants and small insertions and deletions, using desktop sequencers and predesigned commercial kits. Despite these trends, a diversity of approaches to testing exists. Conclusions.— This information should be useful to further inform a variety of topics, including national discussions involving clinical laboratory quality systems, regulation and oversight of next-generation sequencing–based oncology testing, and precision oncology efforts in a data-driven manner.


Author(s):  
Maheen Nisar

Rapid progress is being made in the development of next-generation sequencing (NGS) technologies, allowing repeated findings of new genes and a more in-depth analysis of genetic polymorphisms behind the pathogenesis of a disease. In a field such as psychiatry, characteristic of vague and highly variable somatic manifestations, these technologies have brought great advances towards diagnosing various psychiatric and mental disorders, identifying high-risk individuals and towards more effective corresponding treatment. Psychiatry has the difficult task of diagnosing and treating mental disorders without being able to invariably and definitively establish the properties of its illness. This calls for diagnostic technologies that go beyond the traditional ways of gene manipulation to more advanced methods mainly focusing on new gene polymorphism discoveries, one of them being NGS. This enables the identification of hundreds of common and rare genetic variations contributing to behavioral and psychological conditions. Clinical NGS has been useful to detect copy number and single nucleotide variants and to identify structural rearrangements that have been challenging for standard bioinformatics algorithms. The main objective of this article is to review the recent applications of NGS in the diagnosis of major psychiatric disorders, and hence gauge the extent of its impact in the field. A comprehensive PubMed search was conducted and papers published from 2013-2018 were included, using the keywords, “schizophrenia” or “bipolar disorder” or “depressive disorder” or “attention deficit disorder” or “autism spectrum disorder” and “next-generation sequencing”


HLA ◽  
2021 ◽  
Author(s):  
Mei San Tang ◽  
Brian F. Duffy ◽  
Jo‐Ellen Jennemann ◽  
Bijal A. Parikh ◽  
Chang Liu

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