Orphanet is a “disorder” centric resource, in contrast to OMIM (Online Mendelian Inheritance in Man), which defines entries on their genetic basis. To date more than 7,000 disorders are included in the Orphanet database and new disorders are added regularly.
Orphanet contains a hierarchical clinical classification of rare disorders; which is organized into medical specialities such as rare genetic disorders, rare cardiac disorders etc). Orphanet also assigns each disorder a phenome type. Phenome is defined as ‘a set of phenotypes expressed at the cell, tissue, organ or organism level. It describes the “physical totality of all traits of an organism or of one of its subsystems”’.
The database integrates (in a number of languages) the nosology (or classification) of rare diseases, their relationship with genes and epidemiological data, cross-references to other terminologies, databases and classifications.