STAT1 and hyperinsulinemic hypoglycemia, familial, 4: Primary immunodeficiencies, including the hyper-IgE syndrome (n = 4), STAT-1 mutation (n = 2), T-cell deficiency (n = 1), interferon-gamma-receptor-1 deficiency (n = 1), common variable immunodeficiency (n = 1) and hemophagocytic lymphohistiocytosis (n = 1), as well as HIV, were the most common cause of immunosuppression (20.4% and 18.4%, respectively), followed by a history of renal transplantation (16.3%).