Short answer
Whole genome sequencing looks across nearly all of a person's DNA, while whole exome sequencing focuses on the protein-coding portion. In clinical care, these tests are often used for complex or unexplained conditions. In consumer settings, the report may include uncertain findings, secondary findings, ancestry-dependent interpretation, and results that still need clinical confirmation.
What WGS can and cannot tell you
| Report type | What it may tell you | Main limit |
|---|---|---|
| Whole genome sequencing | Variants across most of the genome, including noncoding regions. | Large data volume does not guarantee clear clinical meaning. |
| Whole exome sequencing | Variants in the protein-coding regions of genes. | May miss important changes outside exons. |
| Consumer genomic report | Selected health, ancestry, or trait reports from a consumer company. | Different companies test different variants and may interpret them differently. |
What to clarify before buying or acting
| Question | Why it matters |
|---|---|
| Is this clinical-grade testing or a consumer report? | Clinical tests have different ordering, confirmation, counseling, and reporting workflows. |
| What variant types are reliably detected? | Coverage, structural variants, repeat expansions, mitochondrial DNA, and pharmacogenomic variants may vary. |
| How are variants classified? | Pathogenic, likely pathogenic, benign, and variants of uncertain significance carry different meaning. |
| Can the data be reanalyzed later? | Interpretation changes as science and databases improve. |
| Who controls raw data and samples? | Genome data has privacy implications for you and biological relatives. |
Why VUS matters
A variant of uncertain significance, or VUS, means the lab found a change but does not yet know whether it is related to disease. NHGRI notes that the great majority of new variants cannot be classified confidently at first. A VUS usually should not drive major medical decisions by itself, and family studies or future reclassification may change how it is viewed.
Privacy and family implications
Genetic information is shared across biological relatives, so one report can matter to more than one person. NHGRI also warns that DTC genetic data can be handled by third-party companies and may raise privacy concerns. GINA helps with health insurance and employment, but HHS notes that it does not cover life insurance, disability insurance, or long-term care insurance.
Important limits
- A negative report does not rule out every genetic condition.
- A variant of uncertain significance should not usually drive major medical action by itself.
- Consumer reports may not include every clinically relevant gene, variant type, or interpretation update.
- Family history can matter even when sequencing does not find a clear answer.
- Clinical confirmation and genetic counseling can change how a result should be used.
Questions to ask
- Is this whole genome sequencing, whole exome sequencing, or a smaller panel?
- What types of variants are included and which ones are not?
- Are secondary findings reported, and can I opt out?
- Will the lab offer reanalysis later if knowledge changes?
- Who can access my raw data, and what happens if I delete the account?
Related guides: direct-to-consumer genetic testing, raw DNA upload privacy risks, FDA-authorized genetic tests, and when to use a genetic counselor.
FAQ
How is whole genome sequencing different from whole exome sequencing?
WGS looks across nearly all of the DNA, while WES focuses on the protein-coding portion. WGS can see more, but more data does not always mean more certainty.
What is a VUS?
A VUS is a variant of uncertain significance. It is a real change in the DNA, but the lab does not yet know whether it is related to disease.
Should a VUS change treatment or surgery plans?
Usually not by itself. A VUS is meant to be revisited in clinical context, and it may be reclassified later.
Can I assume a negative report rules out genetic disease?
No. No sequencing report catches everything, and some conditions involve variant types or regions that a given assay may miss.
Can I ask for reanalysis later?
Often yes, but the policy depends on the lab. Reanalysis can matter because variant interpretation changes as databases and research improve.
What privacy issue should I think about first?
Think about who stores your raw data, who can share it, and what happens if you upload it to a third-party service. Genetic data can matter for your relatives as well as you.