Chronic granulomatous disease is caused by an X chromosome-linked granulocyte function defect whereby the superoxide radical (O2-) and hydrogen peroxide are not formed during phagocytosis. In the course of the investigation of the family of a boy with chronic granulomatosis disease carriers could not be established using the NBT test. Only determination of O2- formation by granulocytes during phagocytosis led to identification of disease carriers. This may possibly represent a means for prenatal diagnosis.
