Severe clinical forms of cytochrome b-negative chronic granulomatous disease (X91-) in 3 brothers with a point mutation in the promoter region of CYBB.
Chronic granulomatous disease (CGD) is a rare congenital syndrome that results in severe, recurrent bacterial and fungal infections. The most common form is caused by defects in the CYBB gene, leading to the absence of gp91phox associated with totally abolished NADPH oxidase activity (X91(0) CGD). We report 3 brothers with atypical cases of X-linked CGD, characterized by low levels of expression of gp91phox (X91(-) CGD). A point mutation (T-55C) identified in the CYBB gene's promoter region appears to prevent the full expression of this gene in neutrophils. This results in low levels of expression of gp91phox protein that are correlated with residual oxidase activity in the whole population of neutrophils. The total O(2)(-) production in these cells was approximately 5% of normal. Despite this oxidase activity, the patients experienced severe and life-threatening infections. It was concluded that the O(2)(-) production in the neutrophils of these patients was not sufficient to protect them against infections, and this X91(-) CGD phenotype must be considered to be a severe clinical form of CGD.
Stasia
Marie José
MJ
GREPI EA 2938, Laboratoire d'Enzymologie, Centre Hospitalier Universitaire, Grenoble, France. MJStasia@chu-grenoble.fr.
Brion
Jean-Paul
JP
Boutonnat
Jean
J
Morel
Françoise
F
D001483:Base Sequence; D045303:Cytochromes b / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D006105:Granulomatous Disease, Chronic / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D010375:Pedigree; D010587:Phagocytosis / Q000235:genetics; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012313:RNA / Q000737:chemistry / Q000235:genetics; D011971:Receptors, Immunologic / Q000378:metabolism; D011982:Receptors, Prostaglandin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism
D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D011982:Receptors, Prostaglandin; D013481:Superoxides; D009580:Nitroblue Tetrazolium; D012313:RNA; D045303:Cytochromes b; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C036293:prostaglandin D2 receptor