BACKGROUND: Oncopanel genomic testing, which identifies important somatic variants, is increasingly common in medical practice and especially in clinical trials. Currently, there is a paucity of reliable genomic reference samples having a suitably large number of pre-identified variants for properly assessing oncopanel assay analytical quality and performance. The FDA-led Sequencing and Quality Control Phase 2 (SEQC2) consortium analyze ten diverse cancer cell lines individually and their pool, termed Sample A, to develop a reference sample with suitably large numbers of coding positions with known (variant) positives and negatives for properly evaluating oncopanel analytical performance. RESULTS: In reference Sample A, we identify more than 40,000 variants down to 1% allele frequency with more than 25,000 variants having less than 20% allele frequency with 1653 variants in COSMIC-related genes. This is 5-100× more than existing commercially available samples. We also identify an unprecedented number of negative positions in coding regions, allowing statistical rigor in assessing limit-of-detection, sensitivity, and precision. Over 300 loci are randomly selected and independently verified via droplet digital PCR with 100% concordance. Agilent normal reference Sample B can be admixed with Sample A to create new samples with a similar number of known variants at much lower allele frequency than what exists in Sample A natively, including known variants having allele frequency of 0.02%, a range suitable for assessing liquid biopsy panels. CONCLUSION: These new reference samples and their admixtures provide superior capability for performing oncopanel quality control, analytical accuracy, and validation for small to large oncopanels and liquid biopsy assays.
- MeSH
- alely * MeSH
- frekvence genu * MeSH
- genetická heterogenita MeSH
- genetická variace * MeSH
- genetické testování metody normy MeSH
- genomika metody normy MeSH
- lidé MeSH
- nádorové biomarkery * MeSH
- nádorové buněčné linie MeSH
- nádory diagnóza genetika MeSH
- průběh práce MeSH
- variabilita počtu kopií segmentů DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
DNA conformation may deviate from the classical B-form in ∼13% of the human genome. Non-B DNA regulates many cellular processes; however, its effects on DNA polymerization speed and accuracy have not been investigated genome-wide. Such an inquiry is critical for understanding neurological diseases and cancer genome instability. Here, we present the first simultaneous examination of DNA polymerization kinetics and errors in the human genome sequenced with Single-Molecule Real-Time (SMRT) technology. We show that polymerization speed differs between non-B and B-DNA: It decelerates at G-quadruplexes and fluctuates periodically at disease-causing tandem repeats. Analyzing polymerization kinetics profiles, we predict and validate experimentally non-B DNA formation for a novel motif. We demonstrate that several non-B motifs affect sequencing errors (e.g., G-quadruplexes increase error rates), and that sequencing errors are positively associated with polymerase slowdown. Finally, we show that highly divergent G4 motifs have pronounced polymerization slowdown and high sequencing error rates, suggesting similar mechanisms for sequencing errors and germline mutations.
- MeSH
- DNA chemie MeSH
- G-kvadruplexy MeSH
- genomika * metody normy MeSH
- kinetika MeSH
- konformace nukleové kyseliny * MeSH
- lidé MeSH
- mutace MeSH
- nukleotidové motivy MeSH
- replikace DNA MeSH
- reprodukovatelnost výsledků MeSH
- sekvenční analýza DNA * metody MeSH
- vysoce účinné nukleotidové sekvenování * metody normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: The repertoire of T- and B-cell receptor sequences encodes the antigen specificity of adaptive immunity system, determines its present state and guides its ability to mount effective response against encountered antigens in future. High throughput sequencing of immune repertoires (Rep-Seq) is a promising technique that allows to profile millions of antigen receptors of an individual in a single experiment. While a substantial number of tools for mapping and assembling Rep-Seq data were published recently, the field still lacks an intuitive and flexible tool that can be used by researchers with little or no computational background for in-depth analysis of immune repertoire profiles. RESULTS: Here we report VDJviz, a web tool that can be used to browse, analyze and perform quality control of Rep-Seq results generated by various pre-processing software. On a set of real data examples we show that VDJviz can be used to explore key repertoire characteristics such as spectratype, repertoire clonality, V-(D)-J recombination patterns and to identify shared clonotypes. We also demonstrate the utility of VDJviz in detection of critical Rep-Seq biases such as artificial repertoire diversity and cross-sample contamination. CONCLUSIONS: VDJviz is a versatile and lightweight tool that can be easily employed by biologists, immunologists and immunogeneticists for routine analysis and quality control of Rep-Seq data. The software is freely available for non-commercial purposes, and can be downloaded from: https://github.com/antigenomics/vdjviz .
- MeSH
- B-lymfocyty imunologie metabolismus MeSH
- genomika metody normy MeSH
- hypervariabilní oblasti genetika MeSH
- internetový prohlížeč MeSH
- klonální evoluce genetika MeSH
- lidé MeSH
- shluková analýza MeSH
- software * MeSH
- T-lymfocyty imunologie metabolismus MeSH
- V(D)J rekombinace * MeSH
- výpočetní biologie metody normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- diagnostické techniky molekulární metody využití MeSH
- genetika normy statistika a číselné údaje trendy MeSH
- genomika normy statistika a číselné údaje trendy MeSH
- lidé MeSH
- molekulární biologie metody statistika a číselné údaje trendy MeSH
- řízení kvality MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- směrnice pro lékařskou praxi MeSH
- MeSH
- diagnostické techniky molekulární metody využití MeSH
- genetika normy statistika a číselné údaje trendy MeSH
- genomika metody normy statistika a číselné údaje MeSH
- lidé MeSH
- molekulární biologie metody statistika a číselné údaje trendy MeSH
- řízení kvality MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- směrnice pro lékařskou praxi MeSH
