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Basic Characteristics of Mutations
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Mutation Site
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D3L |
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Mutation Site Sentence
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The N gene coding sequence of SARS-CoV-2 with and without the D3L mutation (specific for B.1.1.7) was cloned into pCR II-TOPO vectors to validate polymorphism-dependent N gene dropout with the AllplexSARS-CoV-2/FluA/FluB/RSVPCR assay. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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N |
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Standardized Encoding Gene
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N
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Genotype/Subtype
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B.1.1.7 |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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COVID-19
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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- |
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Literature Information
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PMID
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34044153
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Title
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SARS-CoV-2 N gene dropout and N gene Ct value shift as indicator for the presence of B.1.1.7 lineage in a commercial multiplex PCR assay
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Author
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Wollschlager P,Todt D,Gerlitz N,Pfaender S,Bollinger T,Sing A,Dangel A,Ackermann N,Korn K,Ensser A,Steinmann E,Buhl M,Steinmann J
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Journal
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Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
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Journal Info
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2021 Sep;27(9):1353
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Abstract
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OBJECTIVES: Detection and surveillance of SARS-CoV-2 is of eminent importance, particularly due to the rapid emergence of variants of concern (VOCs). In this study we evaluated if a commercially available quantitative real-time PCR (qRT-PCR) assay can identify SARS-CoV-2 B.1.1.7 lineage samples by a specific N gene dropout or Ct value shift compared with the S or RdRp gene. METHODS: VOC B.1.1.7 and non-B.1.1.7 SARS-CoV-2-positive patient samples were identified via whole-genome sequencing and variant-specific PCR. Confirmed B.1.1.7 (n = 48) and non-B.1.1.7 samples (n = 58) were analysed using the Allplex SARS-CoV-2/FluA/FluB/RSV PCR assay for presence of SARS-CoV-2 S, RdRp and N genes. The N gene coding sequence of SARS-CoV-2 with and without the D3L mutation (specific for B.1.1.7) was cloned into pCRII-TOPO vectors to validate polymorphism-dependent N gene dropout with the Allplex SARS-CoV-2/FluA/FluB/RSV PCR assay. RESULTS: All studied B.1.1.7-positive patient samples showed significantly higher Ct values in qRT-PCR (Delta6-10, N gene dropout on Ct values > 29) of N gene than the corresponding values of S (p = 0.0001) and RdRp (p = 0.0001) genes. The assay reliably discriminated B.1.1.7 and non-B.1.1.7 positive samples (area under the curve = 1) in a receiver operating characteristic curve analysis. Identical Ct value shifts (Delta7-10) were detected in reverse genetic experiments, using isolated plasmids containing N gene coding sequences corresponding to D3 or 3L variants. DISCUSSION: An N gene dropout or Ct value shift is shown for B.1.1.7-positive samples in the Allplex SARS-CoV-2/FluA/FluB/RSV PCR assay. This approach can be used as a rapid tool for B.1.1.7 detection in single assay high throughput diagnostics.
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Sequence Data
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-
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