All 16,403 rare disease classes in the Mondo Disease Ontology were assessed against six prioritisation criteria. How each one was determined:
Evidence is thin or absent for several of these, so the final selection of 3,079 diseases was made by consensus among the clinical and health-informatics experts on the team rather than by a score. Only 140 could be placed with confidence in the higher-prevalence band of roughly 10–50 per 100,000.