Among patients treated in the ICU settings there were patients with a diagnosis of chronic granulomatous disease (n = 1), trisomy 21 (n = 1), Wiskott-Aldrich syndrome (n = 1), nuclear factor κB mutation (NFKB2) (n = 1) and X-linked inhibitor of apoptosis protein (XIAP) deficiency (n = 1). The gene discussed is XIAP; the disease is Wiskott-Aldrich syndrome.