The Orphanet nomenclature is a multilingual, standardized, controlled medical terminology specific to rare diseases. Each clinical entity (generic technical term used to describe the clinical items included in the nomenclature of rare diseases) is associated with a unique numerical identifier named ORPHAcode, as well as a preferred term, synonyms, and a definition. The ORPHAcode provides a common language across healthcare and research systems for effective monitoring and reporting on rare diseases, thus improving their visibility.
Each clinical entity is attributed one classification level (Group of disorders, Disorder, or Subtype of disorder), and is included in as many medical specialties as necessary according to its clinical presentation. A disorder in the database can be a disease, a malformation syndrome, a clinical syndrome, a morphological or a biological anomaly or a particular clinical situation (in the course of a disorder).
The nomenclature is organised in a multi-hierarchical and polyparental classification, structured by medical specialty according to diagnostic and therapeutic relevance.
In order to better define rare disorders of genetic origin, Orphanet provides information on every gene related to a rare disorder. This information includes the genetic international nomenclature, the gene typology, the chromosomal location, the cross-mappings with other international genetic databases. Orphanet also defines the relationship between genes and their related rare disorders and provides the evidence for establishing these gene-disorder relationships
The ORPHADATA has been translated into many languages including English, Dutch, French, German, Italian, Portuguese, Spanish, Polish and Czech. More information at the official Orphanet webpage.