Orphanet together with the European Bioinformatics Institute jointly developed the Orphanet Rare Disease Ontology (ORDO) capturing the relationships between rare diseases, genes and other related information. ORDO also contains links to other biomedical ontologies, databases, and classification systems.

Orphan and rare diseases include more familiar conditions such as cystic fibrosis, Lou Gehrig's disease and Tourette's syndrome, as well as less familiar conditions such as Duncan's Syndrome, Madelung's disease and acromegaly/gigantism.

The ORPHANET is a database dedicated to providing information on rare diseases and orphan drugs.

Citing articles in Orphanet Journal of Rare Diseases Article citations follow this format: Authors: Title. Orphanet J Rare Dis [year], [volume number]:[article number].