Molecular characterization of autosomal recessive chronic granulomatous disease caused by a defect of the nicotinamide adenine dinucleotide phosphate (reduced form) oxidase component p67-phox.
Chronic granulomatous disease (CGD) is a rare inherited disorder of phagocytes in which defective production of microbicidal oxidants leads to severe recurrent infections. CGD is caused by mutations in any of 4 genes encoding components of nicotinamide adenine dinucleotide phosphate (reduced form; NADPH) oxidase, the multisubunit enzyme that produces the precursor of these oxidants, superoxide. Approximately 5% of CGD patients have an autosomal recessive form of disease caused by a severe deficiency of p67-phox, a 526-amino acid subunit of the oxidase that appears to regulate electron transport within the enzyme. Here we report the biochemical and molecular characterization of 6 unrelated kindreds with p67-phox deficiency. These studies show that, as in gp91-phox and p22-phox deficiencies, the p67-phox CGD patients show a high degree of heterogeneity in the genetic defects that underlie their disease. Five different mutant alleles were identified: (1) a nonsense mutation in exon 4 (C(304) --> T); (2) a 5-nucleotide (nt) deletion in exon 13 (nts 1169-1173); (3) a splice mutation in the first nucleotide of intron 4 (G --> A); (4) a deletion of 1 nt in exon 9 (A(728)); and (5) a 9-nt in-frame deletion in exon 2 (nts 55-63). The splice mutation was seen in 3 unrelated kindreds, while the 5-nt deletion was seen in 2 apparently unrelated families (both of Palestinian origin). Homozygosity was present in 4 of the kindreds, 2 of which had consanguineous parentage. In the isolated neutrophils of each of the affected patients in the 6 kindreds, there was no measurable respiratory burst activity and no p67-phox protein detected by immunoblot analysis. The level of 67-phox mRNA was less than 10% of normal in the mononuclear leukocytes from 3 of the 4 patients analyzed by Northern blot studies. Thus, this heterogeneous group of mutations in p67-phox all lead to marked instability of mRNA or protein (or both) that results in the complete loss of NADPH oxidase activity.
Patiño
P J
PJ
Department of Immunology, Genentech, Inc, South San Francisco, CA, USA.
Rae
J
J
Noack
D
D
Erickson
R
R
Ding
J
J
de Olarte
D G
DG
Curnutte
J T
JT
D000293:Adolescent; D000483:Alleles; D017398:Alternative Splicing; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D017931:DNA Primers; D005091:Exons; D005260:Female; D005808:Genes, Recessive; D006105:Granulomatous Disease, Chronic / Q000097:blood / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D020125:Mutation, Missense; D019255:NADPH Oxidases / Q000172:deficiency / Q000235:genetics*; D009504:Neutrophils / Q000201:enzymology*; D009679:Nuclear Family; D010750:Phosphoproteins / Q000172:deficiency* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion
D017931:DNA Primers; D046911:Macromolecular Substances; D010750:Phosphoproteins; C079789:neutrophil cytosol factor 67K; D019255:NADPH Oxidases