Chronic granulomatous disease due to different mutations in patients from the same consanguineous extended family

Chronic granulomatous disease is a primary immunodeficiency disease caused by a genetic mutation in any of the 5 genes encoding the different components of the Nicotinamide Adenine Dinucleotide Phosphate reduced (NADPH)-Oxidase enzyme complex. Since primary immunodeficiency diseases are considered to be rare diseases, the genetic diagnosis of a certain primary immunodeficiency leads to the reasonable assumption that all patients with the same disease within the same family will have the same genetic mutation. We report 2 patients with chronic granulomatous disease from the same extended consanguineous family who had different genetic causes of their disease. Therefore, it is crucial to obtain a definitive genetic diagnosis of primary immunodeficiency disease even in patients from the same family, where the same genetic diagnosis is presumed to be the cause of the disease. Statement of novelty: Genetic causes of chronic granulomatous disease may be different in patients from the same family.