2,000 to 2,500 patients live with Dravet syndrome in the UK. Within that population, 400 to 500 carry a molecularly confirmed SCN1A diagnosis, and 600 to 900 remain inadequately controlled on cannabidiol plus fenfluramine, the refractory pool this model sizes precisely.
UK Dravet prevalence estimates require reconciling two internally-tracked figures rather than reading either in isolation. NHS Genomic Medicine Service and Dravet UK Society data put the total UK Dravet population at 2,000 to 2,500 patients, of whom an estimated 400 to 500 carry a molecularly confirmed de novo SCN1A mutation actively tracked in genetic registries, a narrower confirmed-diagnosis subset rather than a competing total. Clinical molecular confirmation runs at roughly 75 percent of diagnosed cases, and the NHS Genomic Medicine Service offers SCN1A testing free of charge, with a fast-track route under two weeks for infantile encephalopathy presentations.
Treatment share now follows a fixed NICE-defined sequence. An estimated 1,500 to 2,000 patients are on cannabidiol, and 400 to 600 have stepped up to the combined cannabidiol-plus-fenfluramine regimen after inadequate response. Even on that combined background, 600 to 900 UK patients fail to reach a 50 percent or greater seizure reduction, concentrated at six to eight NHS specialist paediatric epilepsy centres. This refractory cohort, not the broader Dravet population, is the addressable NICE submission target for any new entrant.
UK Dravet syndrome funnel — from estimated prevalence to the refractory, treatment-eligible pool
| Funnel Stage | Population | Source |
|---|---|---|
| Estimated total UK Dravet syndrome prevalence | 2,000-2,500 | Dravet UK Society / NHS Genomic Medicine Service |
| SCN1A-molecularly-confirmed subset (genetic registries) | 400-500 | NHS GMS epilepsy gene panel data |
| On cannabidiol (Epidiolex) | 1,500-2,000 | NICE TA614 commissioning data |
| On combined cannabidiol plus fenfluramine | 400-600 | NICE TA808 commissioning data |
| Inadequately controlled on combined therapy | 600-900 | NICE TA614/TA808 commissioning data |
Sources: NICE TA614 and TA808 Final Appraisal Determinations; NHS Genomic Medicine Service epilepsy gene panel specifications; Dravet UK Society data 2023.
What this model answers
Every section answers a named commercial question your team is asking, scoped to your asset.
Delivers
- Total UK prevalence (2,000-2,500, Dravet UK Society/NHS GMS)
- the 400-500 SCN1A-confirmed registry subset within it
- why the two figures describe one population, not two competing totals
Delivers
- Cannabidiol (TA614) and fenfluramine (TA808) commissioning status
- the 1,500-2,000 on CBD and 400-600 on combined therapy
- the cardiac-monitoring access barrier that keeps some patients off fenfluramine
Delivers
- 8-sheet structure (Strategic Context, Inputs, Model, Projections, Sensitivity, References, Market Context, QC)
- formula-driven, zero hardcoded cells
- NHS GMS/NICE/Dravet UK Society source citation per step
Custom model delivered in 72 hours.
Commission This ModelWhat's inside
- Why the confirmed-registry subset, not total prevalence alone, sets the addressable population
- Reconciling the 400-500 confirmed figure against the 2,000-2,500 total before the rest of the model is built out
- 2,000-2,500 estimated UK Dravet prevalence (Dravet UK Society)
- SCN1A confirmation running at roughly 75% of diagnosed cases (NHS GMS)
- 400-500 molecularly-confirmed patients tracked in UK genetic registries
- NHS GMS free gene-panel testing and fast-track referral pathway
- 1,500-2,000 on cannabidiol; 400-600 on combined CBD-plus-fenfluramine
- NICE TA614/TA808 commissioning sequence
- 600-900 inadequately controlled on combined therapy
- Concentration at 6-8 NHS specialist paediatric epilepsy centres
- Which assumptions move the refractory pool most
- Scenario ranges across confirmed-registry and total-prevalence bases
- Patient volume by horizon under conservative, base, and aggressive scenarios
- Revenue translation inputs
- The open questions your forecasting team must close before the model is finalised
- Structured for an internal forecast-review session
Included with every brief
How AXLRx builds this model
Prepared by MoatRx analysts.
Every AXLRx patient flow model is built on a five-layer funnel: population, disease burden (E1), diagnosis and specialist capture (E2), treatment and biomarker eligibility (E3), market access (E4), then Year 1-3-5 projections across three scenarios. Delivered as a live Excel workbook, not a static table, with formula-driven sheets and zero hardcoded cells.
UK Dravet syndrome sources: NICE TA614 and TA808 commissioning documents, NHS Genomic Medicine Service epilepsy gene panel data, and Dravet UK Society prevalence and registry figures. Where two internal figures described the same population at different resolutions, the broader total and the narrower confirmed subset are presented together, not as competing counts.
- UK total Dravet prevalence (2,000-2,500) verified against Dravet UK Society data and NHS Genomic Medicine Service framing
- SCN1A-confirmed registry subset (400-500) and the ~75% clinical confirmation rate verified against NHS GMS epilepsy gene panel data
- Cannabidiol/fenfluramine treatment shares and the 600-900 inadequately-controlled cohort verified against NICE TA614 and TA808 commissioning documents
Frequently asked questions
Commission this model
AXLRx delivers rare disease patient flow models built for forecasting and launch teams sizing the UK Dravet syndrome opportunity. Custom model in 72 hours.
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