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.
Delivers
- 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
Delivers
- 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
Delivers
- 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
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Commission This ModelWhat's inside
- 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
- 37-centre national survey methodology and the 1,152 confirmed Type I/II count
- Why this is the strongest bottom-up figure available
- UK HAE Alliance's ~1:32,000 prevalence rate applied to the UK population
- The ~2,000-patient top-down cross-check
- 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
- Where the three methods agree and diverge
- The undiagnosed/non-specialist-engaged gap as the explanation
- The full triangulated model, re-runnable with your own assumptions
- The open sizing questions your team must close before the number is used in planning
Included with every brief
How AXLRx builds this model
Prepared by MoatRx analysts.
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
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.
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