Orphanet
Overview
Orphanet is a European rare disease reference portal managed by INSERM and funded by the European Commission, providing a comprehensive nomenclature, classification, and encyclopaedia of rare diseases and orphan drugs. Founded in France in 1997 and expanded to a European consortium, it assigns unique ORPHAcodes to rare disease entities that serve as standard identifiers for data harmonisation across clinical registries, EHR systems, and research databases. Orphanet covers over 6,000 rare disease entities as of 2024, with structured information on prevalence, clinical features, causative genes, diagnostic criteria, and specialist care centres across 40 countries. The ORDO (Orphanet Rare Disease Ontology) is a formal ontology derived from the Orphanet nomenclature, aligned with SNOMED CT, ICD-10, MeSH, and HPO, and governed under the OBO Foundry.