The disease develops as a result of mutations in any of the 5 genes encoding the nicotinamide-adenine-dinucleotide-phosphate (NADPH) oxidase complex, i.e., CYBB (encodes the gp91phox protein and causes X-linked CGD), CEBA, NCF1, NCF2 and NCF4 (encode p22phox, p47phox, p67phox and p40phox proteins, respectively, and cause AR CGD) [58, 59]. Here, NCF4 is linked to chronic granulomatous disease.