Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.9 (glucose-6-phosphatase)
 3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glycogen storage disease (GSD) type 1a (von Gierke disease) is an autosomal recessive disorder caused by a deficiency in microsomal glucose-6-phosphatase (G6Pase). We have identified a novel mutation in the G6Pase gene of a individual with GSD type 1a. The cDNA from the patient's liver revealed a 91-nt deletion in exon 5. The genomic DNA from the patient's white blood cells revealed no deletion or mutation at the splicing junction of intron 4 and exon 5. The 3' splicing occurred 91 bp from the 5' site of exon 5 (at position 732 in the coding region), causing a substitution of a single nucleotide (G to T) at position 727 in the coding region. Further confirmation of the missplicing was obtained by transient expression of allelic minigene constructs into animal cells. Another eight unrelated families of nine Japanese patients were all found to have this mutation. This mutation is a new type of splicing mutation in the G6Pase gene, and 91% of patients and carriers suffering from GSD1a in Japan are detectable with this splicing mutation.
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PMID:Exon redefinition by a point mutation within exon 5 of the glucose-6-phosphatase gene is the major cause of glycogen storage disease type 1a in Japan. 766 82

Glycogen storage disease type la (GSD1a) is an autosomal recessive metabolic disorder caused by a deficiency in glucose-6-phosphatase (G6Pase). We analyzed the G6Pase genes of two unrelated Chinese families with GSD1a. DNA sequencing of all five exons and the exon-intron boundaries revealed a G T transversion at nucleotide 727 (727G-->T) in exon 5, which has previously been reported to cause abnormal splicing. In one family, the subject and her affected sister were confirmed to be homozygous for this mutation and their parents to be heterozygotes. In the other family, the proband was identified to be heterozygous for this mutation, and a novel mutation, the 341delG in exon 2, was identified. This mutation alters the reading frame and creates a stop codon TAA 15 codons downstream from the mutation, resulting in a truncated protein. Family studies revealed that the father was heterozygous for the 727G-->T mutation and that the mother was heterozygous for the 341delG mutation. This is the first time that the 727G T mutation has been found in Chinese patients or outside Japan. Since we only tested two GSD1a families and found 727G-->T in both, we believe that this mutation may also be prevalent in our local Chinese population. To investigate allele frequencies, we screened 385 Chinese healthy volunteers and found two asymptomatic carriers. Our findings suggest that the 727G-->T mutation is indeed prevalent in Hong Kong.
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PMID:Glucose-6-phosphatase gene (727G-->T) splicing mutation is prevalent in Hong Kong Chinese patients with glycogen storage disease type 1a. 963 72

Recent studies have indicated that the four most common mutations account for 78% of mutant alleles in the glucose-6-phosphatase (G6Pase) gene. A significant fraction of mutant alleles remain unidentified. Thus, informative polymorphic markers are necessary for linkage analysis in carrier testing and prenatal diagnosis in families where mutations can not be identified. The common mutations appear to be ethnic-specific, suggesting that the individual mutations may have a common founder. With the recent discovery of the nucleotide 1176 polymorphism, we have studied whether these mutations are in linkage disequilibrium with the polymorphism. The results of polymerase chain reaction/allele-specific oligonucleotide analysis show that nucleotide 1 176 C is in linkage disequilibrium with mutations R83 C and R83H, and with the splicing mutation 727G-->T. The 1176T polymorphism is in linkage disequilibrium with 459insTA. A GT repeat polymorphism has also been found. However, its heterozygosity is low. The 1176 nucleotide polymorphic marker can be used in carrier and prenatal diagnosis of GSD1a families that have unidentified mutations and are informative for this marker.
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PMID:Linkage disequilibrium and linkage analysis of the glucose-6-phosphatase gene. 1019 Mar 32

Type Ia glycogen storage disease (GSD1a) is an autosomal recessive metabolic disorder caused by a deficiency in glucose-6-phosphatase (G6Pase). Recent cloning of the G6Pase gene and the subsequent identification of several disease-causing mutations have shown an ethnic molecular heterogeneity. Using SSCP analysis and DNA sequencing, we characterized the G6Pase gene of 53 unrelated Italian patients. The two most common mutations, R83C and Q347X, accounted for 66.9% of the mutant alleles. Eight novel mutations and three rare mutations were identified in 15.7% of disease alleles. These results suggest that a DNA-based method can be used as an initial screening in Italian patients clinically suspected of having GSD1a, avoiding liver biopsy for enzymatic diagnosis. In particular, a noninvasive diagnosis is a suitable method for the Italian subpopulation coming from Sicily, where the R83C mutation is present in 80% of mutant alleles. Molecular carrier detection and prenatal diagnosis can be provided to GSD1a families with identified mutation in the propositus.
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PMID:Mutations in the glucose-6-phosphatase gene of 53 Italian patients with glycogen storage disease type Ia. 1007 Jun 17

Glycogen storage disease type 1a (von Gierke disease, GSD1a) is caused by the deficiency of microsomal glucose-6-phosphatase (G6Pase) activity. The cloning of G6Pase cDNA and characterization of the human G6Pase gene enabled the identification of the mutations causing GSD1a. Here we report on the clinical and biochemical features of three GSD1a siblings of a Muslin Arab family with a G270V mutation. Two older patients presented with an unusually mild clinical and biochemical course.
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PMID:Glycogen storage disease type 1a in three siblings with the G270V mutation. 1023 10

A 40-year-old man with glycogen storage disease type 1a (von Gierke disease, GSD1a) developed hepatocellular carcinoma (HCC). Cold single-strand conformation polymorphism (SSCP) with 12% glycerol identified the G727T mutation in the glucose-6-phosphatase (G6Pase) gene, which has been reported to be the most common mutation in Japanese GSD1a patients. This case report is the first documentation of HCC in a case with G727T mutation. Given the prevalence of HCC in GSD1a with various germline mutations, analysis is needed to confirm that the germline mutation in this case is really related to hepatocarcinogenesis. DNA analysis of the family pedigree of this case, revealed three individuals with GSD1a and seven heterozygous carriers of the G727T mutation. As the diagnosis of GSD1a in this family was made only after these three patients reached adulthood, DNA diagnosis may help early identification of GSD1a patients and prevention of the progression of the disease. This DNA-based diagnosis permits prenatal diagnosis in at-risk patients and may facilitate screening and counselling of patients clinically suspected of having this disease.
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PMID:Case report: Hepatocellular carcinoma in type 1a glycogen storage disease with identification of a glucose-6-phosphatase gene mutation in one family. 1038 64

Microsomal glucose-6-phosphatase-alpha (G6Pase-alpha) and glucose 6-phosphate transporter (G6PT) work together to increase blood glucose concentrations by performing the terminal step in both glycogenolysis and gluconeogenesis. Deficiency of the G6PT in liver gives rise to glycogen storage disease type 1b (GSD1b), whereas deficiency of G6Pase-alpha leads to GSD1a. G6Pase-alpha shares its substrate (glucose 6-phosphate; G6P) with hexose-6-phosphate-dehydrogenase (H6PDH), a microsomal enzyme that regenerates NADPH within the endoplasmic reticulum lumen, thereby conferring reductase activity upon 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). 11beta-HSD1 interconverts hormonally active C11beta-hydroxy steroids (cortisol in humans and corticosterone in rodents) to inactive C11-oxo steroids (cortisone and 11-dehydrocorticosterone, respectively). In vivo reductase activity predominates, generating active glucocorticoid. We hypothesized that substrate (G6P) availability to H6PDH in patients with GSD1b and GSD1a will decrease or increase 11beta-HSD1 reductase activity, respectively. We investigated 11beta-HSD1 activity in GSD1b and GSD1a mice and in two patients with GSD1b and five patients diagnosed with GSD1a. We confirmed our hypothesis by assessing 11beta-HSD1 in vivo and in vitro, revealing a significant decrease in reductase activity in GSD1b animals and patients, whereas GSD1a patients showed a marked increase in activity. The cellular trafficking of G6P therefore directly regulates 11beta-HSD1 reductase activity and provides a novel link between glucose metabolism and function of the hypothalamo-pituitary-adrenal axis.
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PMID:11beta-Hydroxysteroid Dehydrogenase Type 1 Regulation by Intracellular Glucose 6-Phosphate Provides Evidence for a Novel Link between Glucose Metabolism and Hypothalamo-Pituitary-Adrenal Axis Function. 1758 37

Type 1a glycogen storage disease (GSD 1a), or von Gierke disease, is a rare, autosomal-recessive disease caused by a deficiency of glucose-6-phosphatase, which leads to glycogen accumulation in the liver, kidney, and intestinal mucosa. Clinical manifestations include hypoglycemia, growth retardation, hepatomegaly, lactic acidemia, hyperlipidemia, and hyperuricemia. Long-term complications include renal disease, gout, osteoporosis, pulmonary hypertension, short stature, and hepatocellular adenomas, which may undergo malignant transformation. Herein we have described the management and the clinical course of a GSD1a patient who underwent simultaneous preemptive liver- kidney transplantation (SPLKT), which solved the liver and renal disease. We confirmed the rapid normalization of glucose metabolism, and correction of hyperlipemia after liver transplantation. In our opinion uremic patients with GSD 1a with or without adenomas must be considered for SPLKT. To our knowledge this is the fifth case of SPLKT and the first preemptive one to be described in the literature.
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PMID:Preemptive liver-kidney transplantation in von Gierke disease: a case report. 2162 87