11/64. Hepatic glycogen synthetase deficiency. Definition of syndrome from metabolic and enzyme studies on a 9-year-old girl.In the 13 years since hepatic glycogen synthetase deficiency was first described in identical twins no further cases seem to have been observed. We report a child who had suffered from occasional morning convulsions since the age of 7. Three 24-hour metabolic profiles showed fasting hypoglycaemia, hyperketonaemia, but normal lactate. Hyperglycaemia and hyperlactataemia occurred after meals. glucagon caused a rise in glucose 3 hours after a meal with a fall in lactate and alanine; no effect of glucagon was seen after a 12-hour fast. Normal increments in glucose followed oral galactose or alanine. liver and abdominal wall muscle biopsies were taken. glycogen content was subnormal in liver but normal in muscle. glycogen synthetase (EC 2.4.1.11) was virtually absent from liver but fully active in muscle. Hepatic glycogen synthetase deficiency causing fasting hypoglycaemia has been confirmed. It is postulated that some children with "ketotic hypoglycaemia" may suffer from this disorder.- - - - - - - - - - ranking = 1keywords = deficiency (Clic here for more details about this article) |
12/64. Permanent neonatal diabetes caused by glucokinase deficiency: inborn error of the glucose-insulin signaling pathway.Neonatal diabetes can be either permanent or transient. We have recently shown that permanent neonatal diabetes can result from complete deficiency of glucokinase activity. Here we report three new cases of glucokinase-related permanent neonatal diabetes. The probands had intrauterine growth retardation (birth weight <1,900 g) and insulin-treated diabetes from birth (diagnosis within the first week of life). One of the subjects was homozygous for the missense mutation Ala378Val (A378V), which is an inactivating mutation with an activity index of only 0.2% of wild-type glucokinase activity. The second subject was homozygous for a mutation in the splice donor site of exon 8 (intervening sequence 8 [IVS8] 2T-->G), which is predicted to lead to the synthesis of an inactive protein. The third subject (second cousin of subject 2) was a compound heterozygote with one allele having the splice-site mutation IVS8 2T-->G and the other the missense mutation Gly264Ser (G264S), a mutation with an activity index of 86% of normal activity. The five subjects with permanent neonatal diabetes due to glucokinase deficiency identified to date are characterized by intrauterine growth retardation, permanent insulin-requiring diabetes from the first day of life, and hyperglycemia in both parents. Autosomal recessive inheritance and enzyme deficiency are features typical for an inborn error of metabolism, which occurred in the glucose-insulin signaling pathway in these subjects.- - - - - - - - - - ranking = 1.1666666666667keywords = deficiency (Clic here for more details about this article) |
13/64. GLUT-1 deficiency without epilepsy--an exceptional case.The GLUT-1 deficiency is a metabolic disorder caused by a defect in glucose transport across the blood-brain barrier as a result of a defect in the glucose-transport protein. patients present with epileptic seizures, delayed development, ataxia and hypotonia, and in many cases acquired microcephaly. In most patients, treatment with a ketogenic diet proved to be successful in controlling the epilepsy. We report a 9-year-old boy with retardation and ataxia, but without epilepsy, caused by GLUT-1 deficiency, proven biochemically and by dna analysis. Treatment with a medium-chain triglyceride ketogenic diet had a beneficial effect.- - - - - - - - - - ranking = 1keywords = deficiency (Clic here for more details about this article) |
14/64. Congenital disorder of glycosylation (CDG) type Ie. A new patient.CDG Ie is caused by a deficiency of dolichol-phosphate-mannose synthase 1 (DPM1), an enzyme involved in N-glycan assembly in the endoplasmic reticulum. Three proteins are known to be part of the synthase complex: DPM 1, DPM2 and DPM3. Only mutations in DPM1, the catalytic subunit, have been described in three families. One was homozygous for the c274C>G (R92G) mutation in DPM1 and two others were compound heterozygous for R92G and a c628delC deletion or a c331-343del13, respectively. Clinical features were a severe infantile encephalopathy, early intractable seizures, acquired microcephaly, and some dysmorphic features. We report a patient with milder symptoms: microcephaly, dysmorphic features, developmental delay, optic atrophy, and cerebellar dysfunction without cerebellar atrophy. The patient is homozygous for a new mutation in exon 9 of the DPM1 gene (c742T>C (S248P)). Our findings extend the spectrum of CDG Ie.- - - - - - - - - - ranking = 0.16666666666667keywords = deficiency (Clic here for more details about this article) |
15/64. Clinical presentation, EEG studies, and novel mutations in two cases of GLUT1 deficiency syndrome in japan.We report the first two Japanese children diagnosed with glucose transporter type 1 (GLUT1) deficiency syndrome. Both boys had been treated under the initial diagnosis of epilepsy and were reinvestigated for previously unexplainable hypoglycorrhachia. Myoclonic seizures developed at 4 months of age in Patient #1 (7 years old), and at 2 months of age in Patient #2 (11 years old), followed by cerebellar ataxia, spastic diplegia, and mental retardation. Both patients had hypoglycorrhachia, and the symptoms were more severe in the latter. CSF and serum glucose levels determined simultaneously showed a CSF/serum glucose ratio of below 0.4 in both patients. In mildly affected Patient #1, the postprandial waking EEG showed improvement in the background activity, as compared to that recorded after overnight fasting, while no significant changes were observed in severely affected Patient #2. In both patients, the functional GLUT1 defect was confirmed by 3-O-methyl-D-glucose uptake into erythrocytes. Molecular analyses identified heterozygous novel mutations in both patients, within exons 6 and 2 of the GLUT1 gene, respectively. The ketogenic diet was refused in Patient #1, but started in Patient #2 with significant clinical benefit. fasting CSF analysis and pre-/postprandial EEG changes in children with epileptic seizures and unexplainable neurological deterioration help in diagnosing this potentially treatable disorder.- - - - - - - - - - ranking = 0.83333333333333keywords = deficiency (Clic here for more details about this article) |
16/64. Novel mutation (Gly280Ala) in the ATP-binding domain of glycerol kinase causes severe hyperglycerolemia.glycerol kinase deficiency is a rarely diagnosed X-linked recessive disorder which occurs as a complex form together with the adrenal hypoplasia congenita (AHC) or with Duchenne muscular dystrophy (DMD) or as an isolated form either symptomatic or asymptomatic. We report the case of a male adult who had pseudo-hypertriglyceridemia (falsely elevated triglycerides of 552 mg/dl) refractory to lipid-lowering therapy for more than 15 years. Further investigations revealed an isolated, asymptomatic glycerol kinase deficiency. Using polymerase chain reaction and direct dna sequencing, a novel missense mutation Gly280Ala in the Xp21.3 glycerol kinase gene was found. Comparison between human and E.coli glycerol kinase showed that the mutation affects a highly conserved amino acid in an ATP-binding domain in the active centre. This mutation is assumed to destabilize a hydrogen bond between ligand and enzyme resulting in a reduced activity of glycerol kinase and therefore in hyperglycerolemia.- - - - - - - - - - ranking = 0.33333333333333keywords = deficiency (Clic here for more details about this article) |
17/64. Clinical and biochemical presentation of siblings with COG-7 deficiency, a lethal multiple O- and N-glycosylation disorder.congenital disorders of glycosylation (CDG) represent a group of inherited multiorgan diseases caused by defects in the biosynthesis of glycoproteins. We report on two dysmorphic siblings with severe liver disease who died at the age of a few weeks. Increased activities of lysosomal enzymes in plasma were found, though total sialic acid in plasma was strongly decreased. isoelectric focusing of serum sialotransferrins showed a type 2-like CDG pattern. Some of the known CDG subtypes were excluded. O-Glycosylation was investigated by isoelectric focusing of apolipoprotein c-iii, which showed increased fractions of hyposialylated isoforms. In a consecutive study a defect in the conserved oligomeric Golgi complex was established at the level of subunit COG-7, leading to disruption of multiple glycosylation functions of the Golgi. This report on patients with a new variant of CDG, due to a multiple Golgi defect, emphasizes in addition to sialotransferrins the importance of analysis of a serum O-linked glycoprotein, e.g. apolipoprotein c-iii, in unclassified CDG-X cases.- - - - - - - - - - ranking = 0.66666666666667keywords = deficiency (Clic here for more details about this article) |
18/64. Conserved oligomeric Golgi complex subunit 1 deficiency reveals a previously uncharacterized congenital disorder of glycosylation type II.The conserved oligomeric Golgi (COG) complex is a heterooctameric complex that regulates intraGolgi trafficking and the integrity of the Golgi compartment in eukaryotic cells. Here, we describe a patient with a mild form of congenital disorder of glycosylation type II (CDG-II) that is caused by a deficiency in the Cog1 subunit of the complex. This patient has a defect in both N- and O-glycosylation. Mass spectrometric analysis of the structures of the N-linked glycans released from glycoproteins from the patient's serum revealed a reduction in sialic acid and galactose residues. peanut agglutinin (PNA) lectin staining revealed a decrease in sialic acids on core 1 mucin type O-glycans, indicating a combined defect in N- and O-glycosylation. sequence analysis of the COG1 cDNA and gene identified a homozygous insertion of a single nucleotide (2659-2660insC), which is predicted to lead to a premature translation stop and truncation of the C terminus of the Cog1 protein by 80 amino acids. This mutation destabilizes several other COG subunits and alters their subcellular localization and hence the overall integrity of the COG complex. This results in reduced levels and/or altered Golgi localization of alpha-mannosidase II and beta-1,4 galactosyltransferase I, which links it to the glycosylation deficiency. transfection of primary fibroblasts of this patient with the full length hemagglutinin-tagged Cog1 indeed restored beta-1,4 galactosyltransferase Golgi localization. We propose naming this disorder CDG-II/Cog1, or CDG-II caused by Cog1 deficiency.- - - - - - - - - - ranking = 1.1666666666667keywords = deficiency (Clic here for more details about this article) |
19/64. seizures, ataxia, developmental delay and the general paediatrician: glucose transporter 1 deficiency syndrome.AIM: Glucose transporter 1 deficiency syndrome (GLUT1-DS) is an important condition for the general paediatrician's differential armamentarium. We describe a case series of eight patients in order to raise awareness of this treatable neurometabolic condition. The diagnosis of GLUT1-DS is suggested by a decreased absolute cerebrospinal fluid (CSF) glucose value (<2.2 mmol/L) or lowered CSF: plasma glucose ratio (<0.4). methods: This is a review of eight queensland patients with GLUT1-DS. The clinical presentation, clinical course, laboratory investigations and treatment outcomes are discussed. RESULTS: The clinical features noted in our patient cohort include combinations of ataxia, developmental delay and a severe seizure disorder that is refractory to anticonvulsant medications. seizures are the most common clinical manifestation and may be exacerbated by phenobarbitone. The paired CSF: plasma glucose results ranged from 0.2 to 0.39 (normal <0.6) with an average of 0.33. 3-O-Methyl-D-Glucose uptake and GLUT1 Genotyping analysis have been performed on five patients thus far. Rapid and impressive seizure control was observed in 100% of our patients once the ketogenic diet was instituted, with half of the cohort being able to wean completely from anticonvulsants. CONCLUSION: Children presenting with a clinical phenotype consisting of a refractory seizure disorder, ataxia and developmental delay should prompt the consideration of Glucose transporter 1 deficiency syndrome. While the diagnostic test of lumbar puncture is an invasive manoeuvre, the diagnosis provides a viable treatment option, the ketogenic diet. GLUT1-DS displays clinical heterogeneity, but the value of early diagnosis and treatment is demonstrated by our patient cohort.- - - - - - - - - - ranking = 1keywords = deficiency (Clic here for more details about this article) |
20/64. A new mucolipidosis with psychomotor retardation, corneal clouding, and retinal degeneration.A 23-year-old man had slow psychomotor development at 6 months of age and developed intermittent corneal clouding at about 18 months. He developed a truncal ataxia and hypotonia of the limbs combined with spasticity and active deep reflexes that did not progress. His skeleton and facies were normal. Between 1 and 13 years of age, he developed severe optic atrophy, absence of retinal blood vessels, and an extinguished electroretinogram. Biochemical analysis of cultured fibroblasts indicated no lysosomal hydrolase deficiency; cellular metachromasia was absent and there was no mucopolysaccharidoses. Ultrastructural studies indicated single-membrane-limited vacuoles containing lamellated membranes and a polymorphous substance in tissue-cultured cells and conjunctiva.- - - - - - - - - - ranking = 0.16666666666667keywords = deficiency (Clic here for more details about this article) |
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