A Novel Autoimmune Presentation of Wiskott‐Aldrich Syndrome: Type 1 Diabetes

BACKGROUND: Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, and recurrent infections. While autoimmune complications are common in WAS, including autoimmune hemolytic anemia, vasculitis, and glomerulonephritis, type 1 diabetes has not been previously described. CASE PRESENTATION: We report a 37-year-old man with longstanding leukopenia and recurrent infections who was diagnosed with WAS after genetic testing revealed a gain-of-function mutation in the WAS gene. During pre-transplant evaluation for hematopoietic stem cell transplantation, he was incidentally found to have a blood glucose level over 600 mg/dL and an A1c of 12.8%, along with classic symptoms of new-onset diabetes. Antibody testing confirmed autoimmune diabetes with elevated GAD65 and ZnT8 antibodies, and C-peptide of 1.2 ng/mL, with a glucose of 186 mg/dL. He was started on intravenous insulin and later discharged home on a basal-bolus regimen. CONCLUSION: To our knowledge, this is the first reported case of GAD65 and ZnT8 positive autoimmune diabetes in a patient with WAS. This case expands the spectrum of autoimmune disease associated with WAS and underscores the importance of maintaining a high index of suspicion for atypical autoimmune presentations in patients with WAS.