RGD uses the Human Disease Ontology (DO, https://disease-ontology.org/) for disease curation across species. RGD automatically downloads each new release of the ontology on a monthly basis. Some additional terms which are required for RGD's curation purposes but are not currently covered in the official version of DO have been added. As corresponding terms are added to DO, these custom terms are retired and the DO terms substituted in existing annotations and subsequently used for curation.
A synostosis that is characterized by uni- or bilateral fusion of the humerus and radius bones at the elbow level, with or without associated ulnar and carpal/metacarpal deficiency, leading to loss of elbow motion and, in many cases, functional arm incapacity. (DO)