Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.4.1.1 (pyruvate carboxylase)
 1,516 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Children with chronic metabolic acidosis should be investigated to determine the presence of an organic acid, especially when the plasma electrolyte profile shows a deficiency of anion. One of the organic acids that should be looked for in such a patient is lactic acid. Lactic acidosis due to tissue hypoxia is a well-known phenomenon (e.g., in shock and cardiopulmonary disease) and has not been discussed in this essay; nor has lactic acidosis due to exogenous causes like infusion of fructose or sorbitol, or admiministration of phenformin. Chronic lactic acidosis in infancy is a rare condition. It may be associated with glycogen storage disease Type 1, fructose diphosphatase deficiency, methylmalonic acidemia, propionic acidemia, pyruvate carboxylase or dehydrogenase deficiency and Leigh's subacute necrotizing encephalomyelopathy (SNE). Some patients with chronic lactic acidosis do not have nay of these diseases and comprise an "idiopathic" group. This is a heterogeneous group, probably having several different causes for the metabolic error. In Leigh's SNE, a metabolic block in the formation of thiamine triphosphate in brain has been demonstrated and has been attributed to the presence of an inhibitor of thiamine pyrophosphate-adenosine triphosphate (TPP-ATP) phosphoryl transferase in body fluids. The inhibitor has also been encountered in cases of intermittent cerebellar ataxia and of primary hypoventilation (Ondine's curse), which may represent variants of Leigh's disease. Increased blood levels of lactate, pyruvate and alanine frequently are encountered in SNE, but it still is not clear whether they are due to a primary or secondary disturbance in the catabolism of pyruvate. Disturbed lactate and pyruvate metabolism has also been encountered in isolated cases of mental retardation and growth failure, in mitochondrial myopathies and in polyneuropathies, and may be expected to occur in Wernicke's encephalopathy. Finally, it has been noted in malignancy and in association with other rare metabolic disorders.
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PMID:Lactic acidosis in childhood. 17 59

The Institution's experience with hypoglycemia in different types of organic acidemias, branched chain amino acidemia (MSUD), and disorders of fructose metabolism was reviewed retrospectively. The charts of 144 patients who were followed for 1-5 years were studied for the severity and frequency of hypoglycemia. The patients were mainly Saudi; however, 10-25% were from neighboring countries. Therefore, the observations pertain to the genetic groups in the Arabian peninsula. Organic acidemias which primarily manifest with neurologic signs, such as 4-hydroxybutyric aciduria, infantile onset 3-methylglutaconic aciduria, and glutaric aciduria type 1 never showed hypoglycemia. Patients with beta-ketothiolase deficiency, biotinidase deficiency, or intermittent or intermediate MSUD, also did not have hypoglycemia during metabolic crisis. Hypoglycemia was rare and mild among neonates with classic MSUD, ethylmalonic aciduria, and isovaleric acidemia. Less than 50% of the patients with MSUD older than 8 months, pyruvate carboxylase deficiency, methylmalonic acidemia, or propionic acidemia had hypoglycemia during metabolic crisis. On the other hand, patients with 3-hydroxy-3-methyl glutaryl-CoA lyase deficiency, holocarboxylase synthetase deficiency, medium or long-chain acyl-CoA dehydrogenase deficiency, neonatal onset 3-methylglutaconic aciduria, glutaric aciduria type 2, and disorders of fructose metabolism invariably had moderate-to-severe hypoglycemia associated with metabolic crisis. The purpose of this report is to provide the pediatrician, particularly in the Middle East, with a diagnostic guideline to the identification and management of different types of organic acidemias, based on co-existing hypoglycemia.
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PMID:Comparative frequency and severity of hypoglycemia in selected organic acidemias, branched chain amino acidemia, and disorders of fructose metabolism. 772 85

Mitochondrial DNA (mtDNA) depletion refers to a quantitative defect in mtDNA and is heterogeneous with regard to causal genotypes and the associated clinical phenotypes. We report two unrelated infants with mtDNA depletion. A diagnosis of methylmalonic aciduria was initially raised in both on the basis of high urine methylmalonic acid and related organic acids and elevated propionylcarnitine and methylmalonylcarnitine. Carboxylase assay with skin fibroblasts revealed low propionyl-CoA and 3-methylcrotonyl-CoA carboxylase and normal pyruvate carboxylase activities. Quantitative Southern blot analysis of mitochondrial and nuclear DNA with muscle tissues revealed the patients' mtDNA to be depleted to 24% and 39% of normal controls. Our two patients showed multiple mitochondrial dysfunction including respiratory chain defects and deficiencies in the two nuclear DNA encoded carboxylases resulting in abnormal urine organic acids. To our knowledge, there is no obvious connection between the defective pathways other than their mitochondrial locations. These two cases may represent a new entity of mitochondrial disease that might be due to a defective common mechanism, such as assembly, maintenance and transport, affecting various mitochondrial enzymes and functions. Mitochondrial depletion should be considered in infants with atypical organic aciduria that may resemblemethylmalonicaciduria, propionicacidaemia, or 3-methylcrotonyl-CoA carboxylase deficiency.
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PMID:Infantile mitochondrial DNA depletion syndrome associated with methylmalonic aciduria and 3-methylcrotonyl-CoA and propionyl-CoA carboxylase deficiencies in two unrelated patients: a new phenotype of mtDNA depletion syndrome. 1451 28

A 1-year-old boy with methylmalonic acidemia had symmetrical lesions of the bilateral basal ganglia, which suggested Leigh encephalopathy. The findings on brain magnetic resonance imaging (MRI) and his physical condition greatly improved by the intravenous administration of vitamin B1. We hypothesized that in this case, clinical Leigh encephalopathy was caused by a impairment of the activity of pyruvate carboxylase induced by the accumulation of methylmalonyl CoA and an impairment of energy production due to a lack of vitamin B1, especially impairment of the activity of pyruvate dehydrogenase complex during an acute worsening of methylmalonic acidemia. Thus, in the treatment of methylmalonic acidemia, attention should be paid to vitamin B1 deficiency. During an acute worsening, vitamin B1 should be administered by intravenous drip injection.
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PMID:[Case of methylmalonic acidemia presenting clinically Leigh encephalopathy]. 1527 17