Mutational Signatures (v3.5 - November 2025)
SBS88 · GRCh37 · COSMIC v103
Mutational profile
Genome: GRCh37
Genome: GRCh38
Genome: mm9
Genome: mm10
Genome: rn6
Mutational profile using the conventional 96 mutation type classification. This classification is based on the six substitution subtypes: C>A, C>G, C>T, T>A, T>C, and T>G, as well as the nucleotides immediately 5’ and 3’ to the mutation.
Each of the substitutions is referred to by the pyrimidine of the mutated Watson—Crick base pair. Incorporating information on the bases immediately 5’ and 3’ to each mutated base generates 96 possible mutation types (6 types of substitution x 4 types of 5’ base x 4 types of 3’ base). Mutational signatures are displayed and reported based on the observed trinucleotide frequency of the genome, i.e., representing the relative proportions of mutations generated by each signature based on the actual trinucleotide frequencies of the corresponding reference genome.
Proposed aetiology
Exposure to E.coli bacteria carrying pks pathogenicity island, producing genotoxic compound colibactin.
Comments
SBS88 appears to be most active in the first decade of life. Strong preference for adenines at positions -3 and -4 (i.e. 5' of the mutation).
Acceptance criteria
| Background | Identification study | First included in COSMIC | |
|---|---|---|---|
| Lee-Six et al. 2019 Nature / Pleguezuelos-Manzano et al. 2020 Nature / Boot et al. 2020 Genome Research | v3.1 | ||
| Identification | NGS technique | Different variant callers | Multiple sequencing centres |
| WES & WGS | Yes | Yes | |
| Technical validation | Validated in orthogonal techniques | Replicated in additional studies | Extended context enrichment |
| Yes | Yes | Preference for A at -3 bp and -4 bp | |
| Proposed aetiology | Mutational process | Support | |
| Colibactin exposure | Experimental confirmation | ||
| Experimental validation | Experimental study | Species | |
| Pleguezuelos-Manzano et al. 2020 Nature | Human | ||
Summary of the technical and experimental evidence available in the scientific literature regarding the validation of the mutational signature.
Tissue distribution
Mainly found in colorectal cancers, and normal and inflammatory bowel disease-affected colorectal epithelial cells, as well as in some samples derived from head and neck cancer, urinary tract cancer and oral squamous cell carcinoma.
Associated signatures
Associated with ID18, also arising from colibactin exposure.
Replication timing
Topography analysis could not be performed for replication timing as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Nucleosome occupancy
Topography analysis could not be performed for nucleosome occupancy as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
CTCF occupancy
Topography analysis could not be performed for CTCF occupancy as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Histone modifications
Topography analysis could not be performed for histone modifications as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Transcriptional strand asymmetry
Topography analysis could not be performed for transcriptional strand asymmetry as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Genic and intergenic regions
Topography analysis could not be performed for genic and intergenic region asymmetry as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Replicational strand asymmetry
Topography analysis could not be performed for replicational strand asymmetry as the number of mutations satisfying our constraints was insufficient or this signature was not yet analysed.
Strand-coordinated mutagenesis
Topography analysis could not be performed for strand-coordinated mutagenesis as the number of satisfying our constraints was insufficient or this signature was not yet analysed.