Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glycogen storage disease type Ia (GSD-Ia) is an autosomal recessive disorder of glycogen metabolism caused by a deficiency of glucose-6-phosphatase (G6Pase) that is expressed in the liver, kidney, and intestinal mucosa. Clinical manifestations include short stature, hepatomegaly, hypoglycemia, hyperuricemia, and lactic acidemia. To elucidate a spectrum of the G6Pase gene mutations and their frequencies, we analyzed mutations in 51 unrelated Japanese patients with GSD-Ia. The most prevalent mutation was g727t, accounting for 88 of 102 mutant alleles examined, followed by R170X mutation, which accounted for 6 mutant alleles, and R83H mutation which was observed in 3 mutant alleles. In addition, 3 different, novel mutations, IVS1-1g<a, Gly122-to-Asp (G122D) and His179-to-Pro (H179P), were identified. We were able to detect "ectopically" transcribed G6Pase-mRNA in Epstein-Barr virus-transformed lymphoblastoid cells and observed aberrant mRNA splicing associated with the g727t and IVS1-1g<a mutations. To our knowledge, this is the first report that ectopic expression can be utilized for the characterization of GSD-Ia mutations. Our findings suggest that a screening for the g727t, R170X, and R83H mutations by simple DNA-based diagnostic methods can detect 95% of the G6Pase mutant alleles in Japanese patients with GSD-Ia, and remaining mutations can be identified and characterized by the direct sequencing of genomic DNA and/or the analysis of ectopically expressed mRNA. The noninvasive molecular diagnosis for GSD-Ia may ultimately replace the conventional means of enzymatic diagnosis that requires liver biopsy.
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PMID:Glycogen storage disease type Ia: molecular diagnosis of 51 Japanese patients and characterization of splicing mutations by analysis of ectopically transcribed mRNA from lymphoblastoid cells. 1074 7

Glycogen storage disease type Ia (GSD-Ia) is an autosomal recessive disorder of glycogen metabolism caused by glucose-6-phosphatase (G6Pase) deficiency. It is characterized by short stature, hepatomegaly, hypoglycemia, hyperuricemia, and lactic acidemia. Various mutations have been reported in the G6Pase gene (G6PC). However, in Japanese patients, a g727t substitution was found to be the major cause of GSD-Ia, accounting for 20 of 22 mutant alleles [Kajihara et al., 1995], and no other mutations have been found in this population. We analyzed four Japanese GSD-Ia patients and identified three other mutations in addition to the g727t. They included two missense mutations (R83H and P257L) and one nonsense mutation (R170X). Each of the three mutations exhibited markedly decreased G6Pase activity when expressed in COS7 cells. A patient homozygous for R170X showed multiple episodes of profound hypoglycemia associated with convulsions, while P257L was associated with a mild clinical phenotype. The presence of R170X in three unrelated families may implicate that it is another important mutation in the etiology of GSD-Ia in Japanese patients. Thus, the detection of non-g727t mutations is also important in establishing the DNA-based diagnosis of GSD-Ia in this population.
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PMID:Heterogeneous mutations in the glucose-6-phosphatase gene in Japanese patients with glycogen storage disease type Ia. 1079 30

Glycogen storage disease type 1 (GSD-1), also known as von Gierke disease, is a group of autosomal recessive metabolic disorders caused by deficiencies in the activity of the glucose-6-phosphatase (G6Pase) system that consists of at least two membrane proteins, glucose-6-phosphate transporter (G6PT) and G6Pase. G6PT translocates glucose-6-phosphate (G6P) from cytoplasm to the lumen of the endoplasmic reticulum (ER) and G6Pase catalyzes the hydrolysis of G6P to produce glucose and phosphate. Therefore, G6PT and G6Pase work in concert to maintain glucose homeostasis. Deficiencies in G6Pase and G6PT cause GSD-1a and GSD-1b, respectively. Both manifest functional G6Pase deficiency characterized by growth retardation, hypoglycemia, hepatomegaly, kidney enlargement, hyperlipidemia, hyperuricemia, and lactic acidemia. GSD-1b patients also suffer from chronic neutropenia and functional deficiencies of neutrophils and monocytes, resulting in recurrent bacterial infections as well as ulceration of the oral and intestinal mucosa. The G6Pase gene maps to chromosome 17q21 and encodes a 36-kDa glycoprotein that is anchored to the ER by 9 transmembrane helices with its active site facing the lumen. Animal models of GSD-1a have been developed and are being exploited to delineate the disease more precisely and to develop new therapies. The G6PT gene maps to chromosome 11q23 and encodes a 37-kDa protein that is anchored to the ER by 10 transmembrane helices. A functional assay for the recombinant G6PT protein has been established, which showed that G6PT functions as a G6P transporter in the absence of G6Pase. However, microsomal G6P uptake activity was markedly enhanced in the simultaneous presence of G6PT and G6Pase. The cloning of the G6PT gene now permits animal models of GSD-1b to be generated. These recent developments are increasing our understanding of the GSD-l disorders and the G6Pase system, knowledge that will facilitate the development of novel therapeutic approaches for these disorders.
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PMID:The molecular basis of type 1 glycogen storage diseases. 1189 41

Glycogen storage disease type I (GSD-I) is a group of autosomal recessive disorders with an incidence of 1 in 100,000. The two major subtypes are GSD-Ia (MIM232200), caused by a deficiency of glucose-6-phosphatase (G6Pase), and GSD-Ib (MIM232220), caused by a deficiency in the glucose-6-phosphate transporter (G6PT). Both G6Pase and G6PT are associated with the endoplasmic reticulum (ER) membrane. G6PT translocates glucose-6-phosphate (G6P) from the cytoplasm into the lumen of the ER, where G6Pase hydrolyses the G6P into glucose and phosphate. Together G6Pase and G6PT maintain glucose homeostasis. G6Pase is expressed in gluconeogenic tissues, the liver, kidney, and intestine. However G6PT, which transports G6P efficiently only in the presence of G6Pase, is expressed ubiquitously. This suggests that G6PT may play other roles in tissues lacking G6Pase. Both GSD-Ia and GSD-Ib patients manifest phenotypic G6Pase deficiency, characterized by growth retardation, hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, and lactic academia and the current treatment is a dietary therapy. GSD-Ib patients also suffer from chronic neutropenia and functional deficiencies of neutrophils and monocytes, which is treated with granulocyte colony stimulating factor to restore myeloid function. The GSD-Ia and GSD-Ib genes have been cloned. To date, 76 G6Pase and 69 G6PT mutations have been identified in GSD-I patients. A database of the residual enzymatic activity retained by the G6Pase missense mutants is facilitating the correlation of the disease phenotype with the patients' genotype. While the molecular basis for the GSD-I disorders are now known and symptomatic therapies are available, many aspects of the diseases are still poorly understood, and there are no cures. Recently developed animal models of the disorders are now being exploited to delineate the disease more precisely and develop new, more causative therapies.
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PMID:Type I glycogen storage diseases: disorders of the glucose-6-phosphatase complex. 1194 31

Deficiency of glucose-6-phosphatase (G6Pase), a key enzyme in glucose homeostasis, causes glycogen storage disease type Ia (GSD-Ia), an autosomal recessive disorder characterized by growth retardation, hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, and lactic acidemia. G6Pase is an endoplasmic reticulum-associated transmembrane protein expressed primarily in the liver and the kidney. Therefore, enzyme replacement therapy is not feasible using current strategies, but somatic gene therapy, targeting G6Pase to the liver and the kidney, is an attractive possibility. Previously, we reported the development of a mouse model of G6Pase deficiency that closely mimics human GSD-Ia. Using neonatal GSD-Ia mice, we now demonstrate that a combined adeno virus and adeno-associated virus vector-mediated gene transfer leads to sustained G6Pase expression in both the liver and the kidney and corrects the murine GSD-Ia disease for at least 12 months. Our results suggest that human GSD-Ia would be treatable by gene therapy.
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PMID:Sustained hepatic and renal glucose-6-phosphatase expression corrects glycogen storage disease type Ia in mice. 1218 68

OBJECTIVE: To o present up-to-date knowledge about Glycogen storage disease type I (GSD-type I) - a disease caused by the deposit of glycogen resulting from the deficiency of the enzyme glucose-6- phosphatase - and to provide the pediatricians with the necessary information for a precocious diagnosis and an adequate conduct for those cases where this metabolic disturbance is present. METHODS: Through Medline, the most significant articles published during the last 20 years were selected from national and international journals of medicine, with special attention to dietary treatment of glycogen storage disease type I. RESULTS: The metabolism of glycogen and the metabolic consequences of glycogen storage disease type I were discussed, especially hypoglycemia, the principal metabolic disturbance of the disease. The clinical and laboratory findings are described together with the histopathology. The use of uncooked cornstarch and enteral carbohydrate infusion are the means used for the maintenance of normoglycemia. The control of hyperuricemia, hyperlipidemia and platelet disorders are other aspects of the treatment as well as the prevention of infections and the use of G-CSF for glycogen storage type Ib. Hepatic transplant and its principal indications are commented on. Hepatic adenomae, which always have the potential of malignant transformation, are the results of incomplete treatment. CONCLUSIONS: Although it occurs rarely, glycogen storage type I is an important cause of volumous hepatomegaly which is associated with hypoglycemia among the infants. The dietary treatment of this illness has significantly altered the clinical course and has improved the prognosis. Therefore it is indispensable that the general pediatrician should be familiar with the diagnosis of this clinical state so as to act rigorously in favor of the dietary control.
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PMID:[Glycogenosis type I] 1468 23

A 45-year-old patient with von Gierke disease was scheduled for emergency operation due to acute appenditis. He had a significant hepatomegaly and was on oral medication for hyperlipemia and hyperlithuria. General anesthesia was induced with thiopental and suxamethonium, and maintained with nitrous oxide, oxygen, sevoflurane and vecuronium. The perioperative course was uneventful, although the patient revealed mild metabolic acidosis.
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PMID:[Anesthetic management for an emergency operation in a patient with von Gierke disease]. 1610 54

Glycogen storage disease type Ia (GSD Ia; OMIM 232200) is an autosomal recessive disorder of glycogen metabolism caused by a deficiency of the microsomal glucose-6-phosphatase (G6Pase). It is characterized by short stature, hepatomegaly, hypoglycaemia, hyperuricaemia, and lactic acidaemia. Various mutations have been reported in the G6Pase gene (G6PC). In order to determine the mutation spectrum in Tunisia, we performed mutation analysis in 22 Tunisian type I glycogen storage disease (GSD I) patients belonging to 18 unrelated families. All patients were clinically classified as GSD Ia. The R83C mutation was found to be the major cause of GSD Ia, accounting for 24 of 36 mutant alleles (66.6%), The R170Q mutation was the second most frequent mutation; it accounts for 10 of 36 mutant alleles (27.7%). The R83C and R170Q mutations could be rapidly detected by PCR/RFLP. Since the majority of Tunisian patients carried R83C and/or R170Q mutations, we propose direct screening of these mutations as a rapid, valuable and noninvasive tool for diagnosis of GSD Ia in Tunisian as well as in Northern African populations.
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PMID:Mutation spectrum of glycogen storage disease type Ia in Tunisia: implication for molecular diagnosis. 1800 83

Glycogen storage disease type Ia (GSDIa; von Gierke disease; MIM 232200) is caused by a deficiency in glucose-6-phosphatase-alpha. Patients with GSDIa are unable to maintain glucose homeostasis and suffer from severe hypoglycemia, hepatomegaly, hyperlipidemia, hyperuricemia, and lactic acidosis. The canine model of GSDIa is naturally occurring and recapitulates almost all aspects of the human form of disease. We investigated the potential of recombinant adeno-associated virus (rAAV) vector-based therapy to treat the canine model of GSDIa. After delivery of a therapeutic rAAV2/8 vector to a 1-day-old GSDIa dog, improvement was noted as early as 2 weeks posttreatment. Correction was transient, however, and by 2 months posttreatment the rAAV2/8-treated dog could no longer sustain normal blood glucose levels after 1 hr of fasting. The same animal was then dosed with a therapeutic rAAV2/1 vector delivered via the portal vein. Two months after rAAV2/1 dosing, both blood glucose and lactate levels were normal at 4 hr postfasting. With more prolonged fasting, the dog still maintained near-normal glucose concentrations, but lactate levels were elevated by 9 hr, indicating that partial correction was achieved. Dietary glucose supplementation was discontinued starting 1 month after rAAV2/1 delivery and the dog continues to thrive with minimal laboratory abnormalities at 23 months of age (18 months after rAAV2/1 treatment). These results demonstrate that delivery of rAAV vectors can mediate significant correction of the GSDIa phenotype and that gene transfer may be a promising alternative therapy for this disease and other genetic diseases of the liver.
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PMID:Adeno-associated virus-mediated correction of a canine model of glycogen storage disease type Ia. 2016 45

Glycogen storage diseases (GSD) and inborn errors of galactose and fructose metabolism are the most common representatives of inborn errors of carbohydrate metabolism. In this review the focus is set on the current knowledge about clinical symptoms, diagnosis and treatment. Hepatomegaly and hypoglycaemia are the main findings in liver-affecting GSD like type I, III and IX. Diagnosis is usually made by non invasive investigations, e.g. mutation analysis. In GSD I, a carbohydrate balanced diet with frequent meals and nocturnal continuous tube feeding or addition of uncooked corn starch are the mainstays of treatment to prevent hypoglycaemia. Liver transplantation has been performed in different types of GSD. It should only be considered in high risk patients e.g. with substantial cirrhosis. Many countries have included classical galactosaemia in their newborn screening programs. A lactose-free infant formula can be life-saving in affected neonates whereas a strict fructose-restricted diet is indicated in hereditary fructose intolerance.
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PMID:Inborn errors of carbohydrate metabolism. 2095 63


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