Disease Ontology

The Human Disease Ontology (DO) provides a hierarchical, semantically consistent vocabulary for human disease. Originally developed at Northwestern in 2003 and now maintained by an open community led from the University of Maryland School of Medicine, it organises diseases under upper-level branches (e.g. disease of anatomical entity, disease of cellular proliferation, infectious disease, mental health) and cross-references every term to ICD-9/10, MeSH, SNOMED CT, OMIM, Orphanet, NCI Thesaurus, MedDRA and EFO.

DO is OBO Foundry compliant, released under CC0, and is the backbone vocabulary for many downstream tools — Mondo, Open Targets, the Alliance of Genome Resources and the model-organism databases all align to it. New releases ship roughly quarterly via GitHub.