Combined immunodeficiency due to partial RAG1 deficiency is a form of combined T and B cell immunodeficiency (CID; see this term) characterized by severe and persistent cytomegalovirus (CMV) infection and autoimmune cytopenia. The disease is Orphanet rare-disease nomenclature identifier Orphanet_231154 (Combined immunodeficiency T+ B+ due to partial RAG1 deficiency). Also known as: CID T+ B+ due to partial RAG1 deficiency, CID with expansion of gamma delta T cells.