Biallelic Pathogenic Variants in <i>IL2RA</i> Cause Neonatal-Onset Monogenic Autoimmune Diabetes

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. IL2RA should be included in genetic testing for neonatal diabetes and considered in children with diabetes plus immune dysregulation.