Clinical Manifestations and Immunologic Phenotype in Patients With RAG1/2 Mutations: A Single Centre Experience and Description of A Novel Mutation.

Recombination-activating genes (RAG1 and RAG2) encode lymphoid-specific proteins that are essential for V(D)J recombination during early T- and B-lymphocyte development. Biallelic mutations in these genes result in a broad spectrum of primary immunodeficiency phenotypes, ranging from classical severe combined immunodeficiency (SCID) to combined immunodeficiency, immune dysregulation, autoimmunity, and inflammatory complications. The immunological phenotype varies widely, from T-B-NK+ severe combined immunodeficiency (SCID) to combined immunodeficiency (CID), or near-normal T and B cell counts, and even antibody deficiencies despite preserved pathogen-specific antibody responses. In this cohort, we aimed to characterize the clinical, immunological, and genetic features, as well as the disease course, of patients diagnosed with RAG1 and RAG2 deficiencies.