Clinical genetics · London
Whole genome sequencing, read by a clinical genetics team, not an app.
All 3 billion base pairs. Coding regions, non-coding regulatory regions, structural variants, copy number variants, repeat expansions and mitochondrial DNA. Interpreted by consultant clinical geneticists, with counselling before and after.
The test
The highest-resolution genetic test in routine clinical use.
A single blood sample. Roughly 30x coverage of every base in the genome. Interpretation by a consultant clinical geneticist and a genomic multi-disciplinary team, with pre and post-test counselling as standard.
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WGS vs whole exome (WES)
WES covers roughly 2 percent of the genome, the protein-coding regions. WGS covers all 3 billion base pairs, including introns, regulatory regions, mitochondrial DNA and structural variants.
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WGS vs 23andMe / AncestryDNA
Consumer SNP microarrays genotype about 640,000 pre-selected positions. WGS reads the full genome. Consumer results are not validated for clinical decision-making.
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WGS vs single-gene Sanger
Sanger remains the gold standard for confirming one known variant. WGS is the tool when the causative gene is unknown.
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WGS vs targeted panel
A panel is faster and cheaper when the differential is narrow. WGS is preferred when the phenotype is broad or previous testing was negative.
When it is used
Where whole genome sequencing earns its place.
Undiagnosed rare disease, cancer, reproductive planning and complex phenotypes where targeted panels have already returned negative.
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Undiagnosed rare disease
Highest diagnostic yield of any single test. 40 to 60 percent in previously unsolved cases, especially with trio sequencing.
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Repeat expansion disorders
Detects fragile X, myotonic dystrophy, C9orf72, spinocerebellar ataxias and facioscapulohumeral dystrophy that panels and exome miss.
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Structural and copy number variants
Deletions, duplications, inversions and translocations across the whole genome, including non-coding regulatory regions.
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Hereditary cancer risk
Comprehensive alternative when targeted panels are inconclusive, though a focused BRCA or non-BRCA panel is usually first line.
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Somatic tumour profiling
Paired tumour and normal WGS is the NHS Genomic Medicine Service default for eligible cancers.
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Reproductive carrier screening
Broad carrier status across recessive conditions, useful for planning families where a targeted panel is not enough.
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Pharmacogenomic layer
CYP450 and other drug-metabolising variants extracted from the same dataset without extra sequencing.
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Polygenic risk scores
Cardiovascular, diabetes and common-cancer PRS derived from the same file. Clinical utility remains variable.
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Indicative pricing
Honest ranges for London private WGS in 2026.
Prices vary by laboratory, whether counselling is included, and whether reanalysis is bundled. NHS routes remain free where you are eligible.
| Test | Indicative price | Sample | Turnaround |
|---|---|---|---|
| Proband-only WGS (30x coverage) | £2,800 to £6,500 | Blood draw 15 min | 8 to 16 weeks |
| Trio WGS (proband plus two parents) | £5,500 to £11,000 | Blood draw 15 min | 10 to 18 weeks |
| Rapid WGS (critically ill neonate or child) | £8,000 to £15,000 | Blood draw 15 min | 5 to 14 days |
| Somatic tumour and normal WGS (oncology) | £4,500 to £9,500 | Blood plus biopsy | 4 to 8 weeks |
| Reanalysis of existing WGS data | £450 to £1,200 | No new sample | 4 to 8 weeks |
| NHS Genomic Medicine Service (eligible cases) | Free at point of care | Standard clinic | 6 to 12 months |
| Consumer or wellness personal genome (research grade) | £1,200 to £2,500 | Home saliva kit | 8 to 12 weeks |
| Pre-test genetic counselling (1 hour) | £200 to £450 | 45 to 60 min | Same day |
| Post-test genetic counselling and results | £250 to £550 | 60 to 90 min | On results release |
Trio WGS with both biological parents raises diagnostic yield significantly and is preferred where possible. Reanalysis of an existing dataset every 18 to 24 months meaningfully increases yield as new gene-disease evidence emerges.
The journey
From referral to results, in order.
Consent, counselling and multi-disciplinary review are built into the pathway. Nothing is released without a conversation.
- 01 Before
Referral and clinical review
Consultant clinical geneticist or specialist reviews your history, examines HPO phenotype terms and draws the pedigree.
- 02 Before
Pre-test genetic counselling
Discussion of what WGS can and cannot answer, secondary findings on the ACMG SF list, insurance implications under the ABI Concordat 2018, and family cascade.
- 03 Before
Informed consent
Written consent for primary findings, opt-in or opt-out for secondary findings, storage and reanalysis of your data.
- 04 On the day
Sample collection
A blood draw at a partner clinic. Trio testing means parental samples on the same day where possible.
- 05 On the day
Sequencing and analysis
Library preparation, 30x short-read sequencing on Illumina platforms, variant calling and expert clinical interpretation.
- 06 After
Multi-disciplinary review
Pathogenic, likely pathogenic and clinically relevant VUS discussed by a genomic MDT before results are released.
- 07 After
Results and next steps
A 60 to 90 minute counselling session covers the report, treatment implications, family testing and periodic reanalysis.
Consent and ethics
The conversation before the test.
Sequencing your genome has implications for your family, your insurance and your reproductive choices. A proper consent process is not a formality.
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Secondary findings
The ACMG SF list flags around 80 actionable conditions unrelated to the reason for testing. You decide before sequencing whether you want to know.
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Insurance implications
Under the ABI Concordat 2018, UK insurers cannot ask for predictive genetic results for policies below defined thresholds. You should still consider timing.
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Family cascade testing
A pathogenic variant in you may have implications for siblings, parents and children. Cascade testing is offered through the NHS Genomic Medicine Service.
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Reproductive implications
Findings may prompt discussion of preimplantation genetic testing (PGT-M), prenatal diagnosis or partner carrier screening.
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Variants of uncertain significance
Many WGS reports contain a VUS. Classification can change over time as new evidence emerges, which is why reanalysis matters.
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Psychological support
Results can be life-changing even when the news is good. Counselling before, during and after is a core part of the service, not an add-on.
London providers
Where WGS is actually performed in London.
NHS sequencing runs through the seven Genomic Laboratory Hubs. Private services partner with the same infrastructure, with faster access and expanded eligibility.
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NHS Genomic Medicine Service
WGS is the default test for eligible undiagnosed rare disease and paired tumour and normal analysis in cancer. Free where you meet eligibility.
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Genomics England (100,000 Genomes legacy)
National sequencing infrastructure now embedded in the NHS GMS. Continues to deliver research reanalysis for enrolled participants.
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Great Ormond Street Genetics (private)
Paediatric-led clinical genetics service with trio WGS pathways for children with undiagnosed disease.
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King's College Hospital Genomics (private)
Adult and reproductive clinical genetics with access to a South London Genomic Laboratory Hub.
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London Bridge Clinical Genetics
Private consultant-led service partnering with the NHS Genomic Laboratory Hub network for sequencing and interpretation.
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Congenica, Illumina, Verinata
Sequencing and interpretation infrastructure used behind the scenes by the majority of private UK WGS services.
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Nucleotide and Genomics UK
Concierge personal-genome services aimed at consumers seeking research-grade WGS outside the NHS pathway.
Frequently asked
The questions we hear before anyone consents.
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What is the difference between whole genome sequencing and whole exome sequencing?
WGS reads all 3 billion base pairs of DNA, including introns, regulatory regions, mitochondrial DNA, structural variants and repeat expansions. WES reads only the protein-coding regions, about 2 percent of the genome. WES captures roughly 85 percent of known pathogenic variants at lower cost, but WGS has the highest overall diagnostic yield, especially for structural, intronic and repeat-expansion disorders.
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Is a 23andMe or AncestryDNA result the same as whole genome sequencing?
No. Consumer services use SNP microarrays that genotype around 640,000 pre-selected positions across the genome. WGS reads the entire 3 billion base pair sequence. Consumer raw data is not clinically validated and should not be used to make medical decisions. Any concerning finding needs to be confirmed by a clinical laboratory.
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Can I access whole genome sequencing on the NHS?
Yes, through the NHS Genomic Medicine Service, when you meet the eligibility criteria for undiagnosed rare disease or certain cancers. Turnaround is typically 6 to 12 months. Private WGS offers faster access, non-eligible indications, and concierge counselling, at a cost of £2,800 to £11,000 depending on whether you sequence one person or a trio.
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What does a private WGS cost in London?
Proband-only WGS is typically £2,800 to £6,500 privately. Trio WGS with both parents is £5,500 to £11,000 and has a higher diagnostic yield. Rapid WGS for a critically ill child is £8,000 to £15,000. Counselling before and after adds £450 to £1,000. Reanalysis of existing data is £450 to £1,200.
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Will a positive WGS result affect my insurance?
Under the UK ABI Concordat and Moratorium on Genetics and Insurance, insurers cannot ask for predictive genetic test results for life cover below £500,000 or critical illness and income protection below defined thresholds. Larger policies for Huntington disease are the current exception. Discuss timing with an independent adviser before testing.
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What happens if the report finds a variant of uncertain significance?
A VUS means the laboratory cannot yet classify the variant as benign or disease-causing. It is not a diagnosis. Many VUS are reclassified over the years as more evidence emerges, which is why we recommend periodic reanalysis of your data every 18 to 24 months.
Speak to a clinical geneticist
WGS is a serious test. It deserves a serious conversation first.
Tell us what you are trying to answer. We will match you to the right consultant clinical geneticist, arrange counselling and coordinate the sequencing, whether privately or through the NHS Genomic Medicine Service where you are eligible.