In a cohort of 133 patients from 54 unrelated families with genetically confirmed CTLA4 deficiency initial symptoms included autoimmune cytopenia (33%), respiratory manifestations (21%), enteropathy (17%), type 1 diabetes (8%), neurologic symptoms (seizures and headache (6%)), thyroid disease (5%), arthritis (3%), growth retardation, fever or night sweats, atopic dermatitis, or alopecia [87]. Here, CTLA4 is linked to hyperinsulinemic hypoglycemia, familial, 4.