The Sanquin Chronic Granulomatous Disease NGS Panel ( test code X024, X026) includes 7 genes and regions of interest. About 70% of the CGD patients have a defect in the X-linked gene CYBB. The remainder of the patients have a pathogenic variant in NCF1, NCF2, CYBA or NCF4. A loss-of-function mutation or a hypomorphic reduction-in-function mutation in any of these five genes can cause CGD. Glucose-6-phosphate dehydrogenase (G6PD) is included in this gene panel, because G6PD deficiency in severe form may lead to insufficient NADPH formation in leucocytes, thus hampering NADPH oxidase activity. Other genes causing disorders related to CGD, like Rac2 and EROS are also included. Genes causing killing defects, like CARD9, MPO, FPR1, CEBPE, IRAK4 and CTSC will also be included in the updated version of this panel, expected in Q2/2019.