Whole Exome Sequencing

What is Whole Exome Sequencing (WES) test?

Whole Exome Sequencing (WES) sequences the protein‑coding regions of the genome (the exome) to identify genetic variants across >18,000–20,000 genes that may explain a patient’s medical condition, focusing on where most known disease‑causing mutations occur. It is most useful when symptoms suggest a genetic cause but are broad or unclear, enabling a single, comprehensive test instead of multiple sequential gene panels. Results can guide diagnosis, management, surveillance, and genetic counselling.

Why consider Whole Exome Sequencing (WES) test?

• Broad, efficient diagnosis for rare/complex disease: WES surveys all coding genes at once, useful when the phenotype is unclear or genetically heterogeneous, shortening diagnostic odysseys versus sequential single‑gene/panel testing.
• Actionable clinical impact: Findings can direct targeted management, surveillance, and genetic counselling; many labs periodically reanalyse data to capture newly discovered gene–disease links.
• Cost/time advantages vs WGS: WES focuses on exons where most pathogenic variants reside, often providing higher yield per cost and faster analysis than WGS in many clinical scenarios.

Who should get tested for Whole Exome Sequencing (WES) test?

• Patients with suspected genetic disorders after non‑diagnostic prior tests, or when symptoms don’t fit a single gene/panel (e.g., neurodevelopmental delay, epilepsy, cardiomyopathy, metabolic or immunologic conditions, multisystem phenotypes).
• Individuals with early‑onset, severe, or atypical presentations where rapid, comprehensive testing can alter care pathways.
• Cases where sequential testing would be costly/time‑consuming, and a broad first‑line approach is preferred.
• Solo is appropriate when parental samples are unavailable; if feasible, trio testing can help resolve de novo vs inherited variants and slightly increase yield.

More Information Whole Exome Sequencing (WES) test

Other Names: Exome Sequencing, Whole Exome Sequencing, WES

WES is generally strong for single‑nucleotide variants and small indels in exons, but may miss certain variant types (e.g., some copy‑number/structural variants, mosaicism, mitochondrial variants, poorly covered exons, or noncoding changes), so complementary tests may be needed in specific scenarios.