Autoimmune cytopenias were particularly frequent in disorders of immune dysregulation, notably LRBA (100%) and Tripeptidyl peptidase II (TPP2) (100%) deficiencies, and autoimmune lymphoproliferative syndrome (ALPS, 80%), but were also strikingly common in T-cell defects, including CD3γ deficiency (100%) and hypomorphic RAG deficiency (60%). The gene discussed is TPP2; the disease is hyperinsulinemic hypoglycemia, familial, 4.