Key takeaways
- 1,152 Confirmed UK HAE Type I/II patients across 37 specialist centres, Longhurst et al., JACI In Practice 2023, the strongest bottom-up figure
- ~2,000 Top-down estimate applying the UK HAE Alliance's ~1:32,000 prevalence rate to the UK population
- 5,000-6,000 UK HAE Alliance's broader total planning estimate, of which 1,500-2,000 currently receive prophylaxis
- 1,500-2,000 UK HAE patients currently on prophylaxis, the subset of the broader 5,000-6,000 total planning estimate, not the total population itself
Longhurst's 37-centre registry confirms 1,152 UK HAE patients; the UK HAE Alliance's broader planning estimate runs to 5,000-6,000, and the gap between them is the undiagnosed and non-specialist-engaged population.
Three independent methods size the UK HAE population, and each answers a different question. The strongest bottom-up figure comes from Longhurst et al.'s 2023 national survey (JACI In Practice), which identified 1,152 confirmed Type I or Type II HAE patients across 37 specialist centres in England, a registry-grade count of patients actively engaged with specialist HAE care. A top-down estimate, applying the UK HAE Alliance's cited prevalence of roughly 1 in 32,000 to the UK population, implies a total closer to 2,000, a plausible cross-check that sits meaningfully above Longhurst's confirmed count but still well short of the population planning figures used elsewhere in UK HAE commercial work.
The UK HAE Alliance's broader working estimate, the figure used for total addressable-market planning rather than confirmed-registry reporting, runs to 5,000 to 6,000 patients, of which 1,500 to 2,000 are currently on prophylaxis. That broader total is not a contradiction of Longhurst's 1,152; it is a different population definition, one that reaches beyond the 37 centres a single clinical survey could canvas and likely includes undiagnosed patients, those managed outside specialist HAE services, and normal-C1-INH (Type III) presentations that Longhurst's Type I/II-specific survey did not set out to capture. Triangulating the three does not average them into a single number. It identifies the gap between a confirmed specialist-registry count and a broader epidemiological planning estimate as the true undiagnosed and non-specialist-engaged population, the same structural finding that recurs across AXLRx's rare-disease sizing work.
UK HAE sizing — registry count, epidemiology estimate and broader planning total compared
| Sizing Method | Population Estimate | Source |
|---|---|---|
| Registry-based (confirmed Type I/II) | 1,152 patients across 37 centres | Longhurst et al., JACI In Practice, 2023 |
| Epidemiology-based (top-down) | ~2,000 patients (~1:32,000 prevalence) | UK HAE Alliance prevalence estimate |
| Broader planning total (all presentations) | 5,000-6,000 patients | UK HAE Alliance broader working estimate |
| Prophylaxed subset of the broader total | 1,500-2,000 patients | UK HAE Alliance survey 2022-2023 |
Sources: Longhurst HJ et al., J Allergy Clin Immunol In Practice, 2023 (37-centre national survey); UK HAE Alliance annual report 2023; UK HAE Alliance survey 2022-2023; UK national audit of hereditary and acquired angioedema, Clin Exp Immunol, 2013.
What this model answers
Every section answers a named commercial question your team is asking, scoped to your asset.
- Why does Longhurst's 37-centre registry count of 1,152 sit so far below the UK HAE Alliance's broader planning estimate of 5,000-6,000, and which should a forecast use? • Longhurst 2023 methodology and its Type I/II specialist-registry scope • the UK HAE Alliance's broader definition • guidance on which figure fits a given commercial use case
- Is the 1,500-2,000 figure the total UK HAE population or the prophylaxed subset, and how has this been read inconsistently across UK HAE reporting? • The reconciliation: 5,000-6,000 total, of which 1,500-2,000 are on prophylaxis, not a separate total-population estimate • source-by-source mapping of how each figure has been used
- How does the top-down 1:32,000 prevalence estimate cross-check against Longhurst's bottom-up registry count, and what does the remaining gap represent? • Top-down prevalence methodology and the ~2,000-patient implied total • the gap versus Longhurst's 1,152 confirmed cases • diagnostic-delay and specialist-engagement factors explaining it
What's inside
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1 · The Binding Constraint 2 pp
- Why three different UK HAE population figures serve three different purposes, not one contradiction
- Pressure-tested against the Longhurst-vs-Alliance gap before the model is built out
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2 · Registry-Based Sizing — Longhurst 2023 3 pp
- 37-centre national survey methodology and the 1,152 confirmed Type I/II count
- Why this is the strongest bottom-up figure available
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3 · Epidemiology-Based Sizing 3 pp
- UK HAE Alliance's ~1:32,000 prevalence rate applied to the UK population
- The ~2,000-patient top-down cross-check
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4 · Broader Planning Estimate & the Prophylaxed Subset 3 pp
- The 5,000-6,000 total planning figure and its scope beyond Longhurst's survey
- Resolving 1,500-2,000 as the prophylaxed subset, not a competing total
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5 · Triangulation & Confidence Range 3 pp
- Where the three methods agree and diverge
- The undiagnosed/non-specialist-engaged gap as the explanation
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6 · Editable Excel Model —
- The full triangulated model, re-runnable with your own assumptions
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7 · Client Alignment Questions 2 pp
- The open sizing questions your team must close before the number is used in planning
Appendix and source ledger included · 45-minute analyst readout included with delivery
Custom model delivered in 72 hours.
Assess this reportIncluded with every brief
Get Started
Commission this model
AXLRx delivers rare disease market sizing models built for forecasting and strategy teams sizing the UK HAE opportunity. Custom model in 72 hours.
- 1. Submit your requestSpecify your indication, market, and cohort definition.
- 2. Scoping callAXLRx analyst confirms triangulation methods and comparator set before building.
- 3. DeliveryResearch-verified sizing model in 72 hours with optional analyst readout.
How AXLRx builds this model
Prepared by MoatRx analysts on the AXLRx commercial consulting engine.
Every AXLRx market sizing model triangulates at least two independent methods, epidemiology-based and registry-based, before accepting a patient count. This is explicitly a sizing model (static patient count), distinct from a Launch Readiness or forecasting model (dynamic revenue/uptake).
UK HAE sizing sources: Longhurst HJ et al. (JACI In Practice, 2023) for the 37-centre registry count, the UK HAE Alliance annual report 2023 and survey 2022-2023 for the broader planning estimate and prophylaxed-subset figure, and the 2013 UK national audit for historical diagnostic-delay context.
- Longhurst 2023 registry count (1,152 patients, 37 centres) verified against the published survey in JACI In Practice
- UK HAE Alliance's broader planning total (5,000-6,000) and prophylaxed subset (1,500-2,000) verified against the Alliance's annual report 2023 and survey 2022-2023, and reconciled explicitly as total-vs-subset rather than two competing totals
- Top-down epidemiology estimate (~1:32,000 prevalence) verified against the UK HAE Alliance annual report 2023
Frequently asked questions
Deliverables What formats are included with every model?
Every commissioned Market Sizing Model includes an editable 5-sheet Excel model (Cover, Model, Research Validation, QC, Sensitivity) and a PDF methodology brief, no PowerPoint deck. An optional 45-minute analyst readout call is included.
Sources How is the patient count verified?
AXLRx triangulates every sizing estimate across at least two independent methods, registry-based and epidemiology-based, and explicitly reconciles any total-versus-subset ambiguity rather than presenting a single unverified number.
Customisation Can I size a specific subpopulation or NHS commissioning region?
Yes. The intake form captures your indication, target subpopulation, and commissioning region. A scoping call confirms scope before research starts. Commission via the intake form to start.