# Somatic mutations from exome and genome sequencing (WXS, WGS)

Source: https://onco.cc/terms/somatic-mutations-wxs-wgs/  
OnCo record `somatic-mutations-wxs-wgs` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Somatic mutations are the DNA changes a tumour acquired during life; they are read from exome (protein-coding) or whole-genome sequencing of tumour and matched normal tissue.

## Summary

Exome sequencing selects and sequences the protein-coding regions of all genes, about one to two percent of the genome (Wikipedia), and whole genome sequencing determines the entire DNA sequence at once. TCGA relied mainly on exomes, so its mutation data (distributed as MAF files) covers coding changes; whole genomes add non-coding and structural variants. Mutation data is sparse (most genes unmutated in most tumours), which is why it adds little to expression in many prediction tasks.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: WXS; whole-exome sequencing data; somatic mutation data; mutation calls; MAF file; mutation annotation format
- Tags: cansim-terms

## Notes

- Listed in the CanSim terms map 1.0.0 (docs/onco/terms.json, generated 2026-09-24), CC BY 4.0, attribution: CanSim project, an open, public-data-first cancer foundation-model programme; CanSim page path /terms/somatic-mutations.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Exome_sequencing
- Wikipedia: whole genome sequencing: https://en.wikipedia.org/wiki/Whole_genome_sequencing
- Wikipedia: https://en.wikipedia.org/wiki/Exome_sequencing

## Connected records

- terms: [Cancer AI vocabulary (CanSim terms map)](https://onco.cc/terms/cancer-ai-vocabulary/), [Germline vs somatic mutations](https://onco.cc/terms/germline-vs-somatic/), [Targeted panel sequencing](https://onco.cc/terms/targeted-panel-sequencing/), [Tumour mutational burden (TMB)](https://onco.cc/terms/tmb/), [Variant calling](https://onco.cc/terms/variant-calling/)
- technologies: [Whole-exome & whole-genome sequencing](https://onco.cc/technologies/wes-wgs/)

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JSON: https://onco.cc/api/v1/entities/somatic-mutations-wxs-wgs.json