We report five new cases of neonatal or early childhood-onset diabetes caused by biallelic pathogenic variants in IL2RA. Autoimmune diabetes was the presenting feature in most individuals and occurs in 64% of all reported cases of immunodeficiency 41. Patients typically presented in infancy with diabetic ketoacidosis, low C-peptide, and GAD antibody positivity, highlighting an autoimmune etiology. The diabetes phenotype was consistent across cases but not linked to variant type or location. IL2R