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 spermatogenic failure characterized by multiple morphologic abnormalities of the sperm flagella, resulting in reduced or absent progressive sperm motility, that has_material_basis_in homozygous mutation in the DRC1 gene on chromosome 2p23.3. (DO)