Related Experiment Video
Updated: Mar 8, 2026

De novo Identification of Actively Translated Open Reading Frames with Ribosome Profiling Data
Published on: February 18, 2022
Introducing COCOS: codon consequence scanner for annotating reading frame changes induced by stop-lost and frame
Mariusz Butkiewicz1, Jonathan L Haines1, William S Bush1
1Department of Epidemiology and Biostatistics, Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, USA.
Summary:
Reading frame altering genomic variants can impact gene expression levels and the structure of protein products, thus potentially inducing disease phenotypes. Current annotation approaches report the impact of such variants in the context of altered DNA sequence only; attributes of the resulting transcript, reading frame and translated protein product are not reported. To remedy this shortcoming, we present a new genetic annotation approach termed Codon Consequence Scanner (COCOS). Implemented as an Ensembl variant effect predictor (VEP) plugin, COCOS captures amino acid sequence alterations stemming from variants that produce an altered reading frame, such as stop-lost variants and small insertions and deletions (InDels). To highlight its significance, COCOS was applied to data from the 1000 Genomes Project. Transcripts affected by stop-lost variants introduce a median of 15 amino acids, while InDels have a more extensive impact with a median of 66 amino acids being incorporated. Captured sequence alterations are written out in FASTA format and can be further analyzed for impact on the underlying protein structure.
Availability And Implementation:
COCOS is available to all users on github: https://github.com/butkiem/COCOS.
Contact:
mariusz.butkiewicz@case.edu.
Insights
Codon Consequence Scanner (COCOS) annotates genetic variants that alter reading frames, revealing impacts on protein sequences. This tool captures amino acid changes from stop-lost variants and insertions/deletions (InDels), aiding disease phenotype research.
Area of Science:
- Genomics
- Bioinformatics
- Molecular Biology
Background:
- Genomic variants altering reading frames can cause disease by affecting gene expression and protein structure.
- Current annotation methods focus on DNA sequence changes, neglecting downstream transcript and protein alterations.
Purpose of the Study:
- Introduce Codon Consequence Scanner (COCOS), a novel genetic annotation approach.
- To capture and report the effects of reading frame-altering variants on protein sequences.
Main Methods:
- COCOS is implemented as an Ensembl variant effect predictor (VEP) plugin.
- It identifies and analyzes amino acid sequence alterations from stop-lost variants and small insertions/deletions (InDels).
- The tool was applied to data from the 1000 Genomes Project.
Main Results:
- Stop-lost variants altered transcripts by a median of 15 amino acids.
- Small insertions/deletions (InDels) had a more significant impact, incorporating a median of 66 amino acids.
- COCOS outputs captured sequence alterations in FASTA format for further analysis.
Conclusions:
- COCOS addresses the limitation of current annotation approaches by reporting protein-level consequences of reading frame variants.
- The tool provides crucial insights into how genetic variants impact protein structure and potentially induce disease phenotypes.
- COCOS facilitates deeper analysis of variant effects on protein sequences, enhancing genetic research.
More Related Videos
09:34Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
09:58Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models
Published on: December 9, 2016
Related Concept Videos
Point and Frameshift Mutations
Nonsense-mediated mRNA Decay
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Leaky Scanning
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon...
Mutations