Chronic Granulomatous Disease (CGD) is a rare inherited disorder in which patients suffer from severe infection and inflammation. The first indication of disease usually appears in early childhood. The basic defect found to be lie in specialised white blood cells called phagocytic cells, which are responsible for engulfing and destroying germs. In CGD, there is a defect in an enzyme (known as NADPH-oxidase) that is responsible for generating bleach like substances that are important for killing some important germs. In the form of the disease known as X-CGD (which accounts for two thirds of patients), there are defined mistakes in a gene called gp91-phox, which is a key part of the NADPH-oxidase.