CGD chronic granulomatous disease is a rare genetically determined disorder aﬀecting the immune system characterized by recurrent and persistent bacterial and fungal infections due to the inability of the body's phagocytic cells (neutrophil and monocytes) to kill certain phagocytosed microorganisms.). CGD is caused by mutations in one of the ﬁve genes coding for NADPH(nicotinamide adenine dinucleotide phosphate ) oxidase subunits. Approximately 70% of cases are caused by mutations in the CYBB gene leading to X-linked CGD, which often causes a severe form of the disease. More than 700 pathogenic mutations in the CYBB gene encoding the gp91-phox protein have been documented. Other biallelic mutations in CYBA, NCF1, NCF2, and NCF4 cause autosomal recessive CGD. In addition, a novel ER-resident transmembrane protein called Eros (essential for reactive oxygen species) that is essential for the regulation of NADPH oxidase and controls the phagocyte respiratory burst was described. A homozygous CYBC1/EROS mutation was associated with the development of CGD Symptoms usually start in infancy or early childhood. Patients with the X-linked form of CGD (60-70% of patients) tend to present earlier and have more severe disease than patients with autosomal recessive forms. Most X-CGD develop failure to thrive,recurrentbacteriallymphadenitis and pneumonia due to catalase-positive organism especially staphylococcus, also skin, liver,and other internal organs abscesses, and osteomyelitis. In addition, CGD patients are more subjected to invasive lifethreatening fungal infections that aﬀect the lungs and bones. Another problem with patients diagnosed with CGD is the excessive inﬂammatory reactions leading to granulomatous lesions that typically aﬀects the bladder and gastrointestinal tract.~The primary diagnostic tests used in CGD functionally assess the NADPH complex in stimulated neutrophils.The dihydrorhodamine (DHR) assay is the gold standard for diagnosing CGD.~To the investigator's knowledge this will be the first study in Assiut University Children's Hospital to discuss the clinical characteristics and immunological profile of pediatric patients diagnosed as CGD in Assiut University Children's Hospital. In fact there is defect in data about CGD in upper Egypt .
Immunological profile and Clinical characteristics of children diagnosed with chronic granulomatous disease