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 combined T cell and B cell immunodeficiency that is characterized by the onset of recurrent upper and lower respiratory tract infections in early childhood and that has_material_basis_in homozygous or compound heterozygous mutation in the POLD1 gene on chromosome 19q13. (DO)