ORDO — Orphanet Rare Disease Ontology
Overview
ORDO is the Orphanet Rare Disease Ontology, providing the European standard classification of rare diseases with 10,000+ conditions as of 2024, including clinical descriptions, genetic causes, epidemiological data, and disease relationships. Maintained by the Orphanet consortium coordinated by INSERM, ORDO is the mandatory coding system for rare diseases in European Reference Networks (ERNs).
Structure
ORDO organises rare diseases using ORPHA codes at five levels of classification. Disorder denotes a specific rare condition (e.g. ORPHA:899 Rett syndrome). Group of disorders covers clinical or aetiological groupings. Subtype denotes clinical or genetic subtypes. Morphological anomaly covers structural malformations. Biological anomaly covers abnormal biological findings.
Governance
Orphanet is coordinated by INSERM and funded by the European Commission. European Reference Networks, including ERN-RND (rare neurological diseases) and ERN-EpiCARE (rare epilepsies), use ORDO for patient registry coding.
Key Neurological ORPHA Codes
| ORPHA Code | Disease |
|---|---|
| ORPHA:411 | Parkinson’s disease |
| ORPHA:26929 | Alzheimer’s disease |
| ORPHA:282 | Huntington’s disease |
| ORPHA:98895 | Rare cerebellar ataxia (group) |
| ORPHA:208 | Friedreich’s ataxia |
| ORPHA:306695 | CARASIL |
Connections
- Part of: MONDO (ORDO integrated as MONDO sub-hierarchy)
- Part of: OBO Foundry
Resources
- https://www.orpha.net
- https://www.orphadata.com (ORDO SPARQL endpoint and downloads)
- https://www.orpha.net/consor/cgi-bin/Disease.php (disease browser)