Two sizing methods disagree by design: SNRHD's registry count of ~400 confirmed GCC PNH patients sits well below what epidemiology-adjusted prevalence implies, and the gap between them is the diagnostic capacity constraint itself, not measurement error.
Two independent methods size the GCC PNH population, and they disagree for a specific, sourced reason. The registry method counts confirmed diagnoses: Saudi Arabia's National Rare Disease Registry (SNRHD) tracks roughly 400 confirmed PNH cases as of its most recent annual report. The epidemiology method starts from global PNH prevalence rates and adjusts for regional genetics. Consanguinity rates of 25 to 50 percent across Saudi Arabia, the UAE, and Qatar are associated with elevated rates of several autosomal recessive and clonal haematological conditions, and published estimates put true regional PNH prevalence 20 to 30 percent above the global average as a result. Triangulating the two methods does not average them into a single number. It identifies the gap itself as the addressable undiagnosed population.
That gap has a specific, verifiable cause: diagnostic capacity. Fewer than 15 laboratories across all six GCC states offer FLAER flow cytometry, the gold-standard PNH diagnostic, and an estimated 40 to 50 percent of patients remain undiagnosed for more than three years as a result. A sizing model built only on the SNRHD registry count would understate the addressable population by exactly this margin, while a model built only on epidemiology-adjusted prevalence would overstate near-term reachable patients by ignoring the testing bottleneck. Our sensitivity analysis ranks diagnostic capacity as the single assumption most likely to move the total, ahead of prevalence rate itself, which is the opposite of what most naive sizing exercises assume.
GCC PNH sizing — registry count versus epidemiology-adjusted estimate
| Sizing Method | Population Estimate | Source |
|---|---|---|
| Registry-based (confirmed diagnoses) | ~400 patients | SNRHD annual report |
| Epidemiology-based (consanguinity-adjusted) | 20–30% above global prevalence rate | Published regional epidemiology estimates |
| Diagnostic capacity constraint | <15 FLAER-capable labs (6 GCC states) | Regional diagnostic infrastructure survey |
| Estimated undiagnosed share | 40–50% of true PNH population | Derived from registry-epidemiology gap |
Sources: Saudi National Rare Disease Registry (SNRHD) annual report; Al-Jishi EA et al., Saudi Med J 2020; published GCC consanguinity-rate and rare-disease prevalence literature; regional FLAER flow cytometry diagnostic capacity survey.
What this model answers
Every section answers a named commercial question your team is asking, scoped to your asset.
Delivers
- SNRHD registry methodology and its confirmed-case scope
- the consanguinity-adjusted epidemiology estimate
- the specific 20-30% gap between the two methods
Delivers
- Sensitivity ranking of every input
- why diagnostic capacity (fewer than 15 FLAER-capable labs) outranks prevalence rate as the binding constraint
- the undiagnosed-patient estimate this implies
Delivers
- The registry-vs-epidemiology triangulation methodology
- confidence range around the point estimate
- scenario ranges tied to diagnostic-capacity expansion
Custom model delivered in 72 hours.
Commission This ModelWhat's inside
- Why diagnostic capacity, not prevalence rate, is the single assumption that determines whether the total holds up
- Pressure-tested against the SNRHD-vs-epidemiology gap before the rest of the model is built out
- Global PNH prevalence rate adjusted for GCC consanguinity rates (25-50%)
- The 20-30% regional prevalence uplift this implies
- SNRHD confirmed-case count (~400) and its methodology
- Cross-check against the epidemiology-based estimate
- Where the two methods agree and diverge
- The diagnostic-capacity constraint as the explanation for the gap
- Diagnostic capacity ranked above prevalence rate as the binding assumption
- Scenario ranges tied to FLAER lab-capacity expansion
- 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/claims-based, before accepting a patient count. This is explicitly a sizing model (static patient count), distinct from a Patient Flow or forecasting model (dynamic revenue/uptake).
PNH GCC sizing sources: Saudi National Rare Disease Registry (SNRHD) annual report, Al-Jishi EA et al. (Saudi Med J 2020), published GCC consanguinity-rate literature, and a regional FLAER flow cytometry diagnostic capacity survey.
- SNRHD confirmed-case count verified against its most recent annual report
- Consanguinity-adjusted prevalence uplift verified against published GCC consanguinity-rate and rare-disease prevalence literature
- FLAER flow cytometry laboratory capacity verified against a regional diagnostic infrastructure survey
Frequently asked questions
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AXLRx delivers rare disease market sizing models built for forecasting and strategy teams sizing the GCC PNH opportunity. Custom model in 72 hours.
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AXLRx analyst confirms triangulation methods and comparator set before building.
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