scholarly journals Simple and Multiplexed Enrichment of Rare DNA Variants via Sequence-Selective and Temperature-Robust Amplification

2017 ◽  
Author(s):  
Lucia R. Wu ◽  
Sherry X. Chen ◽  
Yalei Wu ◽  
Abhijit A. Patel ◽  
David Yu Zhang
Keyword(s):  
Biological Information ◽  
Sequence Variants ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Lung Cancer Patients ◽  
Dna Sequence Variants ◽  
Pcr Method ◽  
Hybridization Reaction ◽  
Similar Enrichment ◽  
Mutation Allele

Rare DNA sequence variants hold important clinical and biological information, but are chal-lenging for existing methods (e.g. PCR, NGS) to profile in an inexpensive, multiplexed, simple-to-implement, and sequence-general way. Here, we present Blocker Displacement Amplification (BDA), a temperature-robust PCR method that selectively amplifies all sequence variants within a roughly 20 nt window by 1000-fold over wildtype sequences, allowing easy detection and quantitation of hundreds of potentials variants originally at ≤0.1% allele frequency. BDA employs a rationally designed competitive hybridization reaction to achieve similar enrichment performance across anneal temperatures ranging from 56°C to 64°C. This temperature robustness facilitates multiplexed enrichment of many different variants across the genome, and furthermore enables the use of in-expensive and portable thermocycling instruments for rare DNA variant detection. To show the sequence generality of BDA, we demonstrated enrichment on 156 single-nucleotide variants (SNVs). BDA has been validated on multiple different PCR platforms, DNA polymerases, and sample types including clinical cell-free DNA samples collected from the blood plasma of lung cancer patients. BDA quantitation of mutation allele fraction is generally consistent with deep sequencing results.

scholarly journals IL-9 and IL-10 Single-Nucleotide Variants and Serum Levels in Age-Related Macular Degeneration in the Caucasian Population

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Alvita Vilkeviciute ◽  
Dzastina Cebatoriene ◽  
Loresa Kriauciuniene ◽  
Reda Zemaitiene ◽  
Rasa Liutkeviciene
Keyword(s):  
Macular Degeneration ◽  
Serum Levels ◽  
Age Related Macular Degeneration ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Exudative Amd ◽  
Age Related ◽  
Study Results ◽  
Pcr Method ◽  
A Minor

Considering the immunological impairment in age-related macular degeneration (AMD), we aimed to determine the associations of IL-9 rs1859430, rs2069870, rs11741137, rs2069885, and rs2069884 and IL-10 rs1800871, rs1800872, and rs1800896 polymorphisms and their haplotypes, as well as the serum levels of IL-9 and IL-10 with AMD. 1209 participants were enrolled in our study. SNPs were genotyped using TaqMan SNP genotyping assays by real-time PCR method. IL-9 and IL-10 serum levels were evaluated using ELISA kits. Our study results have shown that haplotypes A-G-C-G-G and G-A-T-A-T of IL-9 SNPs are associated with the decreased odds of early AMD occurrence ( p = 0.035 and p = 0.015 , respectively). A set of rare haplotypes was associated with the decreased odds of exudative AMD occurrence ( p = 0.033 ). Also, IL-10 serum levels were lower in exudative AMD than in controls ( p = 0.049 ), patients with early AMD ( p = 0.017 ), and atrophic AMD ( p = 0.008 ). Furthermore, exudative AMD patients with IL-10 rs1800896 CT and TT genotypes had lower IL-10 serum concentrations than those with wild-type (CC) genotype ( p = 0.048 ). In conclusion, our study suggests that IL-10 serum levels can be associated with a minor allele at IL-10 rs1800896 and exudative AMD. The haplotypes of IL-9 SNPs were also associated with the decreased odds of early and exudative AMD.

Single-Nucleotide Variants in microRNAs Sequences or in their Target Genes Might Influence the Risk of Epilepsy: A Review

2021 ◽  
Author(s):  
Renata Parissi Buainain ◽  
Matheus Negri Boschiero ◽  
Bruno Camporeze ◽  
Paulo Henrique Pires de Aguiar ◽  
Fernando Augusto Lima Marson ◽  
...  
Keyword(s):  
Target Genes ◽  
Single Nucleotide Variants ◽  
Single Nucleotide

scholarly journals Combination of Genome-Wide Polymorphisms and Copy Number Variations of Pharmacogenes in Koreans

2021 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Nayoung Han ◽  
Jung Mi Oh ◽  
In-Wha Kim
Keyword(s):  
Copy Number ◽  
Genome Wide Association Study ◽  
Copy Number Gain ◽  
Copy Number Variations ◽  
Gene Gain ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Haplotype Blocks ◽  
Genome Wide ◽  
Control And Prevention

For predicting phenotypes and executing precision medicine, combination analysis of single nucleotide variants (SNVs) genotyping with copy number variations (CNVs) is required. The aim of this study was to discover SNVs or common copy CNVs and examine the combined frequencies of SNVs and CNVs in pharmacogenes using the Korean genome and epidemiology study (KoGES), a consortium project. The genotypes (N = 72,299) and CNV data (N = 1000) were provided by the Korean National Institute of Health, Korea Centers for Disease Control and Prevention. The allele frequencies of SNVs, CNVs, and combined SNVs with CNVs were calculated and haplotype analysis was performed. CYP2D6 rs1065852 (c.100C>T, p.P34S) was the most common variant allele (48.23%). A total of 8454 haplotype blocks in 18 pharmacogenes were estimated. DMD ranked the highest in frequency for gene gain (64.52%), while TPMT ranked the highest in frequency for gene loss (51.80%). Copy number gain of CYP4F2 was observed in 22 subjects; 13 of those subjects were carriers with CYP4F2*3 gain. In the case of TPMT, approximately one-half of the participants (N = 308) had loss of the TPMT*1*1 diplotype. The frequencies of SNVs and CNVs in pharmacogenes were determined using the Korean cohort-based genome-wide association study.

scholarly journals Unsuspected somatic mosaicism for FBN1 gene contributes to Marfan syndrome

2021 ◽  
Author(s):  
Pauline Arnaud ◽  
Hélène Morel ◽  
Olivier Milleron ◽  
Laurent Gouya ◽  
Christine Francannet ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Somatic Mosaicism ◽  
Variant Calling ◽  
Copy Number Variations ◽  
Pathogenic Variant ◽  
Single Nucleotide Variants ◽  
Bioinformatics Analyses ◽  
Single Nucleotide ◽  
Fbn1 Gene ◽  
Pathogenic Variants

Abstract Purpose Individuals with mosaic pathogenic variants in the FBN1 gene are mainly described in the course of familial screening. In the literature, almost all these mosaic individuals are asymptomatic. In this study, we report the experience of our team on more than 5,000 Marfan syndrome (MFS) probands. Methods Next-generation sequencing (NGS) capture technology allowed us to identify five cases of MFS probands who harbored a mosaic pathogenic variant in the FBN1 gene. Results These five sporadic mosaic probands displayed classical features usually seen in Marfan syndrome. Combined with the results of the literature, these rare findings concerned both single-nucleotide variants and copy-number variations. Conclusion This underestimated finding should not be overlooked in the molecular diagnosis of MFS patients and warrants an adaptation of the parameters used in bioinformatics analyses. The five present cases of symptomatic MFS probands harboring a mosaic FBN1 pathogenic variant reinforce the fact that apparently asymptomatic mosaic parents should have a complete clinical examination and a regular cardiovascular follow-up. We advise that individuals with a typical MFS for whom no single-nucleotide pathogenic variant or exon deletion/duplication was identified should be tested by NGS capture panel with an adapted variant calling analysis.

scholarly journals Whole-exome mutational landscape of neuroendocrine carcinomas of the gallbladder

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Fatao Liu ◽  
Yongsheng Li ◽  
Dongjian Ying ◽  
Shimei Qiu ◽  
Yong He ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Large Cell ◽  
Molecular Signatures ◽  
Single Nucleotide Variants ◽  
Oncogenic Signaling ◽  
Single Nucleotide ◽  
Whole Exome ◽  
Deadly Disease ◽  
Oncogenic Signaling Pathways ◽  
Neuroendocrine Carcinomas

AbstractNeuroendocrine carcinoma (NEC) of the gallbladder (GB-NEC) is a rare but extremely malignant subtype of gallbladder cancer (GBC). The genetic and molecular signatures of GB-NEC are poorly understood; thus, molecular targeting is currently unavailable. In the present study, we applied whole-exome sequencing (WES) technology to detect gene mutations and predicted somatic single-nucleotide variants (SNVs) in 15 cases of GB-NEC and 22 cases of general GBC. In 15 GB-NECs, the C > T mutation was predominant among the 6 types of SNVs. TP53 showed the highest mutation frequency (73%, 11/15). Compared with neuroendocrine carcinomas of other organs, significantly mutated genes (SMGs) in GB-NECs were more similar to those in pulmonary large-cell neuroendocrine carcinomas (LCNECs), with driver roles for TP53 and RB1. In the COSMIC database of cancer-related genes, 211 genes were mutated. Strikingly, RB1 (4/15, 27%) and NAB2 (3/15, 20%) mutations were found specifically in GB-NECs; in contrast, mutations in 29 genes, including ERBB2 and ERBB3, were identified exclusively in GBC. Mutations in RB1 and NAB2 were significantly related to downregulation of the RB1 and NAB2 proteins, respectively, according to immunohistochemical (IHC) data (p values = 0.0453 and 0.0303). Clinically actionable genes indicated 23 mutated genes, including ALK, BRCA1, and BRCA2. In addition, potential somatic SNVs predicted by ISOWN and SomVarIUS constituted 6 primary COSMIC mutation signatures (1, 3, 30, 6, 7, and 13) in GB-NEC. Genes carrying somatic SNVs were enriched mainly in oncogenic signaling pathways involving the Notch, WNT, Hippo, and RTK-RAS pathways. In summary, we have systematically identified the mutation landscape of GB-NEC, and these findings may provide mechanistic insights into the specific pathogenesis of this deadly disease.

scholarly journals Missense RHD single nucleotide variants induce weakened D antigen expression by altering splicing and/or protein expression

Transfusion ◽  
2021 ◽  
Author(s):  
Loann Raud ◽  
Marlène Le Tertre ◽  
Léonie Vigneron ◽  
Chandran Ka ◽  
Gaëlle Richard ◽  
...  
Keyword(s):  
Protein Expression ◽  
Antigen Expression ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
D Antigen

scholarly journals scSNV: accurate dscRNA-seq SNV co-expression analysis using duplicate tag collapsing

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gavin W. Wilson ◽  
Mathieu Derouet ◽  
Gail E. Darling ◽  
Jonathan C. Yeung
Keyword(s):  
Genetic Variants ◽  
False Positive ◽  
Variant Calling ◽  
Call Rate ◽  
Rna Seq ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Variant Call ◽  
Two Samples ◽  
Co Detection

AbstractIdentifying single nucleotide variants has become common practice for droplet-based single-cell RNA-seq experiments; however, presently, a pipeline does not exist to maximize variant calling accuracy. Furthermore, molecular duplicates generated in these experiments have not been utilized to optimally detect variant co-expression. Herein, we introduce scSNV designed from the ground up to “collapse” molecular duplicates and accurately identify variants and their co-expression. We demonstrate that scSNV is fast, with a reduced false-positive variant call rate, and enables the co-detection of genetic variants and A>G RNA edits across twenty-two samples.

scholarly journals Structural variant detection in cancer genomes: computational challenges and perspectives for precision oncology

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Ianthe A. E. M. van Belzen ◽  
Alexander Schönhuth ◽  
Patrick Kemmeren ◽  
Jayne Y. Hehir-Kwa
Keyword(s):  
Intratumor Heterogeneity ◽  
Precision Oncology ◽  
Single Nucleotide Variants ◽  
Full Spectrum ◽  
Single Nucleotide ◽  
Sequencing Technologies ◽  
Cancer Genomes ◽  
Genomic Aberrations

AbstractCancer is generally characterized by acquired genomic aberrations in a broad spectrum of types and sizes, ranging from single nucleotide variants to structural variants (SVs). At least 30% of cancers have a known pathogenic SV used in diagnosis or treatment stratification. However, research into the role of SVs in cancer has been limited due to difficulties in detection. Biological and computational challenges confound SV detection in cancer samples, including intratumor heterogeneity, polyploidy, and distinguishing tumor-specific SVs from germline and somatic variants present in healthy cells. Classification of tumor-specific SVs is challenging due to inconsistencies in detected breakpoints, derived variant types and biological complexity of some rearrangements. Full-spectrum SV detection with high recall and precision requires integration of multiple algorithms and sequencing technologies to rescue variants that are difficult to resolve through individual methods. Here, we explore current strategies for integrating SV callsets and to enable the use of tumor-specific SVs in precision oncology.

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