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 1 (GSD-1), also known as von Gierke disease, is caused by a deficiency in the activity of the enzyme glucose-6-phosphatase (G6Pase). It is an autosomal recessive disorder characterized by hypoglycemia, hepatomegaly, kidney enlargement, growth retardation, lactic acidemia, hyperlipidemia and hyperuricemia. The disease presents with both clinical and biochemical heterogeneity consistent with the existence of two major subgroups, GSD-1a and GSD-1b, which have been confirmed at the molecular genetic level. GSD-1a, the most prevalent form, is caused by mutations in the G6Pase gene that abolish or greatly reduce enzymatic activity. The gene maps to chromosome 17q21 and encodes a microsomal transmembrane protein. Animal models of GSD-1a exist and are being exploited to delineate the disease more precisely. It has been proposed that GSD-1b is caused by a defect in the microsomal glucose-6-phosphate transporter. The gene responsible for GSD-1b has been mapped to chromosome 11q23 and a cDNA encoding a microsomal transmembrane protein has been identified. The function of this putative GSD-1b protein remains to be determined. These recent developments, along with newly characterized animal models of GSD-1a, are increasing our understanding of the interrelationship between the components of the G6Pase complex and type 1 glycogen storage diseases.
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PMID:Molecular Genetics of Type 1 Glycogen Storage Diseases. 1032 3

3-Hydroxy-3-Methylglutaryl coenzyme A lyase (HMG-CoA) deficiency is a rare inborn error of leucine catabolism. The disease is characterized by recurrent episodes of metabolic acidosis, hyperammonemia without ketosis, hypoglycemia, lethargy, hepatomegaly, and seizures. This study has evaluated the magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings of three patients with HMG-CoA deficiency. The common findings on all of the MRI scans were multiple, coalescent, marked lesions in periventricular white matter and arcuate fibers, most prominently in frontal or periatrial regions that were superimposed on diffuse, slightly hyperintense subcortical white matter signal. Involvement of the caudate nucleus and the dentate nucleus were observed in the reported patients. MRS studies by both STEAM and PRESS spectra of all patients revealed a decrease in N-acetylaspartate and elevation in both myoinositol and choline. A pathologic peak at 1.33 ppm, which is compatible with lactate, and a particular peak at 2.42 ppm in all patients were also found. The combination of both MRI and MRS findings could be considered as being specific in patients with HMG-CoA lyase deficiency.
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PMID:MRI and MRS in HMG-CoA lyase deficiency. 1037 84

In a personal series of 107 patients, we describe clinical presentations, methods of recognition and therapeutic management of inherited fatty acid oxidation (FAO) defects. As a whole, FAO disorders appear very severe: among the 107 patients, only 57 are still living. Including 47 siblings who died early in infancy, in total 97 patients died, of whom 30% died within the first week of life and 69% before 1 year. Twenty-eight patients presented in the neonatal period with sudden death, heart beat disorders, or neurological distress with various metabolic disturbances. Hepatic presentations were observed in 73% of patients (steatosis, hypoketotic hypoglycaemia, hepatomegaly, Reye syndrome). True hepatic failure was rare (10%); cholestasis was observed in one patient with LCHAD deficiency. Cardiac presentations were observed in 51% of patients: 67% patients presented with cardiomyopathy, mostly hypertrophic, and 47% of patients had heart beat disorders with various conduction abnormalities and arrhythmias responsible for collapse, near-miss and sudden unexpected death. All enzymatic blocks affecting FAO except CPT I and MCAD were found associated with cardiac signs. Muscular signs were observed in 51% of patients (of whom 64% had myalgias or paroxysmal myoglobinuria, and 29% had progressive proximal myopathy). Chronic neurologic presentation was rare, except in LCHAD deficiency (retinitis pigmentosa and peripheral neuropathy). Renal presentation (tubulopathy) and transient renal failure were observed in 27% of patients. The diagnosis of FAO disorders is generally based on the plasma acylcarnitine profile determined by FAB-MS/MS from simple blood spots collected on a Guthrie card. Urinary organic acid profile and total and free plasma carnitine can also be very helpful, mostly in acute attacks. If there is no significant disturbance between attacks, the diagnosis is based upon a long-chain fatty acid loading test, fasting test, and in vitro studies of fatty acid oxidation on fresh lymphocytes or cultured fibroblasts. Treatment includes avoiding fasting or catabolism, suppressing lipolysis, and carnitine supplementation. The long-term dietary therapy aims to prevent periods of fasting and restrict long-chain fatty acid intake with supplementation of medium-chain triglycerides. Despite these therapeutic measures, the long-term prognosis remains uncertain.
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PMID:Recognition and management of fatty acid oxidation defects: a series of 107 patients. 1040 81

We report the case of a two and a half year-old girl who developed fulminant hepatic failure following 5 days of regular oral ingestion of paracetamol, approximately 90 mg x kg-1 x day-1. She presented with the typical findings of hepatomegaly, encephalopathy, high ammonia levels, high transaminases, hypoglycaemia and lactic acidosis. After stabilization, she was transferred to a specialist paediatric liver failure unit and fortunately she made a full recovery with intensive medical management.
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PMID:Paracetamol-induced fulminant hepatic failure in a child after 5 days of therapeutic doses. 1079 55

We report the case of a patient with carbohydrate-deficient glycoprotein syndrome type Ib who developed normally until 3 months of age, when she was referred to the hospital for evaluation of hypoglycemia that was found to be related to hyperinsulinism. She also had vomiting episodes, hepatomegaly, and intractable diarrhea, which evoked the diagnosis of carbohydrate-deficient glycoprotein syndrome. Oral mannose treatment at a dose of 0.17 g/kg body weight 6 times/d was followed by a clinical improvement and normalization of blood glucose, aminotransferases, and coagulation factor levels. Hyperinsulinemic hypoglycemia should be considered as a leading sign of carbohydrate-deficient glycoprotein syndrome type Ib, especially when it is associated with enteropathy and abnormal liver tests.
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PMID:Hyperinsulinemic hypoglycemia as a presenting sign in phosphomannose isomerase deficiency: A new manifestation of carbohydrate-deficient glycoprotein syndrome treatable with mannose. 1048 8

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

Type Ib glycogenosis is a rare glycogen storage disorder resulting from a defect in the enzyme, glucose-6-phosphatase microsomal translocase. We report a case of Type Ib glycogenosis in an 18 month-old male child who presented with a history of hypoglycemic seizures and recurrent infections and had a massive hepatomegaly, recurrent hypoglycemia, hyperuricemia, hypertriglyceridemia, neutropenia and fasting lactacidemia which decreased sharply on glucose administration.
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PMID:Type Ib glycogenosis. 1077 88

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

An unique cytoplasmic inclusion was found in astrocytes of a 2-month-old female baby who showed Leigh-like brain lesions with lactic acidosis, hypoglycemia and hepatomegaly. Although a defective enzyme was not determined, a metabolic disorder was suggested from clinicopathological observations. Symmetrically distributed lesions consisting of marked gliosis and proliferation of capillaries were observed in the basal ganglia, thalami and tegmentum. The astrocytic cytoplasmic inclusion was exclusively found in the cerebral and cerebellar white matter, where myelination was immature. The inclusion was round and eosinophilic, and positive for glial fibrillary acidic protein, vimentin, alphaB-crystallin, S-100 protein and microtubule associated protein 1B, immunohistochemically. An electron microscopic examination revealed an accumulation of intermediate filaments, ribosome and rough endoplasmic reticulum in the inclusion. The characteristic of this inclusion is different from that of other reported inclusions. The inclusion showed positive immunoreaction against CuZn superoxide dismutase, catalase, advanced glycation end-product and 4-hydroxy-2-nonenal antibodies, which suggest that oxidative stress is involved in the genesis of the inclusion.
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PMID:Unique astrocytic inclusion in a 2 month-old baby showing Leigh-like brain lesions with lactic acidosis. 1083 10

Glycogen storage disease type 1a (GSD 1a) is caused by a deficiency in microsomal glucose-6-phosphatase (G6Pase). A variant (GSD 1b) is caused by a defect in the transport of glucose-6-phosphate (G6P) into the microsome and is associated with chronic neutropenia and neutrophil dysfunction. Mutually exclusive mutations in the G6Pase gene and the G6P transport gene establish GSD la and GSD 1b as independent molecular processes and are consistent with a multicomponent translocase catalytic model. A modified translocase/catalytic unit model based on biochemical data in a G6Pase knockout mouse has also been proposed for G6Pase catalysis. This model suggests coupling of G6Pase activity and G6P transport. A 5-mo-old girl with hypoglycemia, hepatomegaly, and lactic acidemia was diagnosed with GSD 1a. She also developed neutropenia, neutrophil dysfunction, and recurrent infections characteristic of GSD 1b. Homozygous G188R mutations of the G6Pase gene were identified, but no mutations in the G6P translocase gene were found. We have subsequently identified a sibling and two unrelated patients with similar genotypic/phenotypic characteristics. The unusual association of neutrophil abnormalities in patients with homozygous G188R mutations in the G6Pase gene supports a modified translocase/catalytic unit model.
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PMID:Glucose-6-phosphatase mutation G188R confers an atypical glycogen storage disease type 1b phenotype. 1096 Apr 98


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