Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q00604 (X-linked)
 16,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The most frequent form of chronic granulomatous disease (CGD) is caused by inactivation of the CYBB gene, which encodes the gp91-phox subunit of phagocyte NADPH oxidase. This defect prevents phagocytes from producing reactive oxygen species and thus from eradicating bacterial and fungal infections. We investigated 16 unrelated male patients with suspected X-linked CGD and gp91-phox deficiency. A mutation was found in the CYBB gene of all 16 patients, and 11 of these mutations were novel. Eleven patients (69%) had a point mutation (84G>A in two unrelated patients, and 177C>G, 217C>T, 388C>T, 676C>T, 691C>T, 868C>T, 919A>C, 1384G>T and T1514G in one case each, yielding W28X, C59W, R73X, R130X, R226X, Q231X, R290X, T307P, E462X, L505R gp-91phox). One patient had an in-frame deletion removing two amino acids (R54 and A55). Finally, insertions or duplications were found in four patients (from +1 to +31 bases). Overall, 12 (75%) of the mutations led to the production of a truncated protein. No clear correlation was found between clinical manifestations and genomic/biochemical alterations. Thirteen mothers could be tested, and all were carriers. Hum Mutat 18:163, 2001.
 ...
PMID:Characterization of 11 novel mutations in the X-linked chronic granulomatous disease (CYBB gene). 1146 41

The most common form of chronic granulomatous disease (CGD) is caused by mutations in the CYBB gene that is carried on the X-chromosome and give rise to the X-linked form of the disease. The product of this gene is the large subunit of flavocytochrome b558, gp91phox, the catalytic core of the superoxide-generating enzyme, NADPH oxidase. In the overwhelming majority of cases, mutations are family-specific and occur in the exonic regions of the gene or, less frequently, at the intron/exon borders. In addition, there are large, often multi-gene, deletions. Four mutations have also been found in the promoter regions. In contrast, very few intronic mutations have been reported. Here we describe an unusual intronic mutation that causes CGD. The mutation is the insertion of 12 bp in intron XI, accompanied by the deletion of exon 12. Remarkably, the grandmother of this patient is chimeric, carrying a normal allele, the patient's allele, and an allele with a 4-nucleotide insertion at a site adjacent to the patient's insertion, in combination with a 1.5-kb deletion within intron XI. The patient's mother carries a normal allele and the patient's allele. We propose that an initial mutational event during the grandmother's embryogenesis has undergone unsuccessful DNA repair and has resulted in two aberrant alleles, one of which has been inherited by the patient and his mother. Remarkably, in the only two kindreds that have been examined in detail where deletions originating within introns have led to CGD, both families have contained members with triple somatic mosaicism.
 ...
PMID:A second case of somatic triple mosaicism in the CYBB gene causing chronic granulomatous disease. 1151 30

The most common, X-linked, form of chronic granulomatous disease (CGD) is caused by mutations in the CYBB gene located at Xp21.1. The product of this gene is the large subunit of flavocytochrome b558, gp91phox, which forms the catalytic core of the antimicrobial superoxide-generating enzyme, NADPH oxidase. In the overwhelming majority of cases, mutations are family-specific and occur in the exonic regions of the gene, or more rarely at the intron/exon borders. Alternatively, they are large (often multi-gene) deletions. In addition, four mutations have been found in the promoter region. In contrast, very few intronic mutations have been reported. Here we describe an intronic mutation that causes X-linked CGD. A single nucleotide substitution in the middle of intron V creates a novel 5' splice site and results in multiple abnormal mRNA products.
 ...
PMID:An unusual intronic mutation in the CYBB gene giving rise to chronic granulomatous disease. 1156 56

We have used a unique polymorphic 3' transduction to show that a human L1, or LINE-1 (long interspersed nucleotide element-1), retrotransposition event most likely occurred in the maternal primary oocyte during meiosis I. We characterized a truncated L1 retrotransposon with a 3' transduction that was inserted, in a Dutch male patient, into the X-linked gene CYBB, thereby causing chronic granulomatous disease. We used the unique flanking sequence to localize the precursor L1 locus, LRE3, to chromosome 2q24.1. In a cell culture assay, the retrotransposition frequency of LRE3 is greater than that for any other element that has been tested to date. The patient's mother had two LRE3 alleles that differed slightly in the 3'-flanking genomic DNA. The patient had a single LRE3 allele that was identical to one of the maternal alleles; however, the patient's insertion matched the maternal LRE3 allele that he did not inherit. Other data indicate that there is only a small chance that the father (unavailable for analysis) carries the precursor LRE3 allele. In addition, paternal origin of the insertion would have required that an LRE3 mRNA transcribed before meiosis II be carried separately from its precursor LRE3 allele in the fertilizing sperm. Since the mother carries a potential precursor allele and the insertion was on the patient's maternal X chromosome, it is highly likely that the insertion originated during maternal meiosis I.
 ...
PMID:Evidence consistent with human L1 retrotransposition in maternal meiosis I. 1209 29

Chronic granulomatous disease (CGD) results from mutations of phagocyte NADPH oxidase. Seventy percent are X-linked (X-)CGD with absent or defective gp91(phox) protein encoded by the CYBB gene. A subset of X-CGD patients demonstrates partial oxidase activity and/or varied levels of the gp91(phox) protein. Definitive genotypic diagnosis in these unusual patients requires mutation analysis. Typically, CYBB mutation analysis has relied on initial screening of cDNA by single-stranded conformation polymorphism analysis, followed by selective sequencing. We report a fluorescent, automated method for CYBB mutation analysis using genomic DNA that provides more rapid and reliable results. Moreover, the use of genomic DNA in this approach allows mutation detection in the mRNA coding region, promoter/enhancer region, and intronic sequences flanking splice junctions and does not require mRNA preparation. The PCR conditions were optimized for each exon, including those with A+T-rich regions. We analyzed DNA from two unusual X-CGD patients and established the genetic basis for their phenotype. We also sequenced 100 normal X chromosomes to establish wild-type consensus sequences and identify polymorphisms.
 ...
PMID:CYBB mutation analysis in X-linked chronic granulomatous disease. 1213 50

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.
 ...
PMID:Severe clinical forms of cytochrome b-negative chronic granulomatous disease (X91-) in 3 brothers with a point mutation in the promoter region of CYBB. 1462 87

Chronic granulomatous disease (CGD) is a fatal genetic disorder in which phagocytes fail to produce antimicrobial superoxide because of NADPH oxidase deficiency. Molecular defects in CYBB gene causing X-linked CGD are responsible for about 70% of all cases. This study was done to confirm genetic defects of CYBB gene in five Korean patients who were highly suggestive of having CGD by clinical history. We performed initial screening for five unrelated Korean patients using single strand conformation polymorphism (SSCP) and then selective sequencing for the regions involving the abnormal bands. Activated NBT tests revealed that all patients were X-linked. SSCP analysis for CYBB gene showed abnormal bands in all patients. The molecular defects of five patients were as follows: c.1663insT, c.1111-1G>T, c.39_40insG, c.927delC and c.434T>C mutation. This result will help the families with prenatal diagnosis or genetic counseling.
 ...
PMID:Molecular analysis of X-linked chronic granulomatous disease in five unrelated Korean patients. 1508 94

Chronic granulomatous disease (CGD) is a rare inherited immunodeficiency syndrome caused by a profound defect in the oxygen metabolic burst machinery. Activity of NADPH oxidase is absent or profoundly diminished, as at least one of its components (gp91(phox), p22(phox), p47(phox) and p67(phox)) is lacking or non-functional. This review explains the molecular basis of NADPH oxidase dysfunction by the effects of mutations in genes coding for particular oxidase components. Among the four types of CGD, the most common is X-linked CGD (approximately 65%), with defects in the CYBB gene encoding gp91(phox). A wide spectrum of mutations has been described in the CYBB gene with no predominant genotype. The second most common subtype of CGD caused by NCF1 mutation accounts for 30% of CGD patients and is inherited in an autosomal recessive manner, with predominance of a homozygotous deltaGT deletion in the genotype. The other two CGD subtypes having an autosomal recessive pattern together account for no more than 10% of CGD cases. A strategy for the molecular diagnostics in CGD patients is proposed and principles of genetic counseling are discussed here.
 ...
PMID:Genetic and biochemical background of chronic granulomatous disease. 1517 25

Most patients with chronic granulomatous disease (CGD) have mutations in the X-linked CYBB gene that encodes gp91phox, a component of the phagocyte NADPH oxidase. The resulting X-linked form of CGD is usually manifested in boys. Rarely, X-CGD is encountered in female carriers with extreme expression of the mutated gene. Here, we report on a woman with a novel mutation in CYBB (CCG[90-92]-->GGT), predicting Tyr30Arg31-->stop, Val in gp91phox, who presented with clinical symptoms at the age of 66. The mutation was present in heterozygous form in genomic DNA from her leukocytes but was fully expressed in mRNA from these cells, indicating that in her leukocytes the X chromosome carrying the nonmutated CYBB allele had been inactivated. Indeed, only 0.4% to 2% of her neutrophils showed NADPH oxidase activity. This extreme skewing of her X-chromosome inactivation was not found in her cheek mucosal cells and is thus not due to a general defect in gene methylation on one X chromosome. Moreover, the CYBB mutation was not present in the DNA from her cheek cells and was barely detectable in the DNA from her memory T lymphocytes. Thus, this patient shows a somatic mosaic for the CYBB mutation, which probably originated during her lifetime in her bone marrow.
 ...
PMID:Unusual late presentation of X-linked chronic granulomatous disease in an adult female with a somatic mosaic for a novel mutation in CYBB. 1530 75

Chronic granulomatous disease is an inherited disorder in which phagocytes lack a functional NADPH oxidase and so cannot generate superoxide anions (O(2) (-)). The most common form is caused by mutations in CYBB encoding gp91 phox, the heavy chain of flavocytochrome b(558) (XCGD). We investigated 11 male patients and their families suspected of suffering from X-linked CGD. These XCGD patients were classified as having different variants (X91(0), X91(-) or X91(+)) according to their cytochrome b(558) expression and NADPH oxidase activity. Nine patients had X91(0) CGD, one had X91(-) CGD and one had X91(+) CGD. Six mutations in CYBB were novel. Of the four new X91(0) CGD cases, three were point mutations: G65A in exon 2, G387T in exon 5 and G970T in exon 9, leading to premature stop codons at positions Try18, Try125 and Glu320, respectively, in gp91 phox. One case of X91(0) CGD originated from a new 1005G deletion detected in exon 9. Surprisingly, four nonsense mutations in exon 5 led to the generation of two mRNAs, one with a normal size containing the mutation and the other in which exon 5 had been spliced. A novel X91(-) CGD case with low gp91 phox expression was diagnosed. It was caused by an 11-bp deletion in the linking region between exon 12 and intron 12, activating a new cryptic site. Finally, a new X91(+) CGD case was detected, characterized by a missense mutation Leu505Arg in the potential NADPH-binding site of gp91 phox. No clear correlation between the severity of the clinical symptoms and the sub-type of XCGD could be established.
 ...
PMID:Characterization of six novel mutations in the CYBB gene leading to different sub-types of X-linked chronic granulomatous disease. 1553 31


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>