Chronic granulomatous disease (CGD) is an inherited disorder characterized by a faulty immune system leading to recurrent and life-threatening bacterial and fungal infections. The most common area of infection is the lungs, but infections also occur in the lymph nodes, liver, bone and skin. CGD can also cause inflammation in different areas of the body, usually in the digestive tract, as well as the stomach, colon, rectum, mouth and throat. The inflammation can obstruct the digestive tract which can keep food from being digested well, so children affected with CGD often grow at a slower rate. In most individuals affected with CGD, symptoms begin to appear before they are five years old, though for some individuals symptoms do not appear until adulthood. Selective use of antibiotics and antifungals has helped to decrease the number of infections over the course of a lifetime and significantly improved life expectancy. Males affected with X-linked CGD, however, tend to have an earlier onset of symptoms, more severe infections, and a slightly shorter life expectancy. Hematopoietic stem cell transplantation can cure CGD, but this treatment is associated with high risks and complications. X-linked CGD is caused by pathogenic variants in the CYBB gene.