Chronic granulomatous disease (CGD) is a group of primary immunodeficiency disorders characterized by defective respiratory bursts in phagocytes, which are caused by mutations in genes encoding subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, including p47phox and p67phox.1 The gene discussed is NCF1; the disease is chronic granulomatous disease.