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Hyperammonemia



Hyperammonemia
Classification & external resources
Ammonia
ICD-10 E72.2
ICD-9 270.6
DiseasesDB 20468
eMedicine neuro/162  ped/1057
MeSH D022124

Hyperammonemia (or 'hyperammonaemia') is a metabolic disturbance characterised by an excess of ammonia in the blood. It is a dangerous condition that may lead to encephalopathy and death. It may be primary or secondary.

Ammonia is a substance that contains nitrogen. It is a product of the catabolism of protein. It is converted to the less toxic substance urea prior to excretion in urine by the kidneys. The metabolic pathways that synthesise urea are located first in the mitochondria and then into the cytosol. The process is known as the urea cycle, which comprises several enzymes acting in sequence.

Contents

Types

Primary vs. secondary

Specific types

In all cases Hyperammonemia results from defects of the Urea cycle. The following list includes such examples:

  • Online 'Mendelian Inheritance in Man' (OMIM) 311250 - hyperammonemia due to ornithine transcarbamylase deficiency
  • Online 'Mendelian Inheritance in Man' (OMIM) 606762 - hyperinsulinism-hyperammonemia syndrome (glutamate dehydrogenase 1)
  • Online 'Mendelian Inheritance in Man' (OMIM) 238970 - hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (ornithine translocase)
  • Online 'Mendelian Inheritance in Man' (OMIM) 237310 - hyperammonemia due to N-acetylglutamate synthetase deficiency
  • Online 'Mendelian Inheritance in Man' (OMIM) 237300 - hyperammonemia due to carbamoyl phosphate synthetase i deficiency (carbamoyl phosphate synthase I)
  • Online 'Mendelian Inheritance in Man' (OMIM) 238750 - hyperlysinuria with hyperammonemia (genetics unknown)

Sequelae

Hyperammonemia is one of the metabolic derangements that contribute to hepatic encephalopathy.

See also


v • d • e
Metabolic pathology / Inborn error of metabolism (E70-90, 270-279)
Amino acidAromatic (Phenylketonuria, Alkaptonuria, Ochronosis, Tyrosinemia, Albinism, Histidinemia) - Organic acidemias (Maple syrup urine disease, Propionic acidemia, Methylmalonic acidemia, Isovaleric acidemia, 3-Methylcrotonyl-CoA carboxylase deficiency) - Transport (Cystinuria, Cystinosis, Hartnup disease, Fanconi syndrome, Oculocerebrorenal syndrome) - Sulfur (Homocystinuria, Cystathioninuria) - Urea cycle disorder (N-Acetylglutamate synthase deficiency, Carbamoyl phosphate synthetase I deficiency, Ornithine transcarbamylase deficiency, Citrullinemia, Argininosuccinic aciduria, Hyperammonemia) - Glutaric acidemia type 1 - Hyperprolinemia - Sarcosinemia
CarbohydrateLactose intolerance - Glycogen storage disease (type I, type II, type III, type IV, type V, type VI, type VII) - fructose metabolism (Fructose intolerance, Fructose bisphosphatase deficiency, Essential fructosuria) - galactose metabolism (Galactosemia, Galactose-1-phosphate uridylyltransferase galactosemia, Galactokinase deficiency) - other intestinal carbohydrate absorption (Glucose-galactose malabsorption, Sucrose intolerance) - pyruvate metabolism and gluconeogenesis (PCD, PDHA) - Pentosuria - Renal glycosuria
Lipid storageSphingolipidoses/Gangliosidoses: GM2 gangliosidoses (Sandhoff disease, Tay-Sachs disease) - GM1 gangliosidoses - Mucolipidosis type IV - Gaucher's disease - Niemann-Pick disease - Farber disease - Fabry's disease - Metachromatic leukodystrophy - Krabbe disease
Neuronal ceroid lipofuscinosis (Batten disease) - Cerebrotendineous xanthomatosis - Cholesteryl ester storage disease (Wolman disease)
Fatty acid metabolismLipoprotein/lipidemias: Hyperlipidemia - Hypercholesterolemia - Familial hypercholesterolemia - Xanthoma - Combined hyperlipidemia - Lecithin cholesterol acyltransferase deficiency - Tangier disease - Abetalipoproteinemia
Fatty acid: Adrenoleukodystrophy - Acyl-coA dehydrogenase (Short-chain, Medium-chain, Long-chain 3-hydroxy, Very long-chain) - Carnitine (Primary, I, II)
MineralCu Wilson's disease/Menkes disease - Fe Haemochromatosis - Zn Acrodermatitis enteropathica - PO43�' Hypophosphatemia/Hypophosphatasia - Mg2+ Hypermagnesemia/Hypomagnesemia - Ca2+ Hypercalcaemia/Hypocalcaemia/Disorders of calcium metabolism
Fluid, electrolyte
and acid-base balance		Electrolyte disturbance - Na+ Hypernatremia/Hyponatremia - Acidosis (Metabolic, Respiratory, Lactic) - Alkalosis (Metabolic, Respiratory) - Mixed disorder of acid-base balance - H2O Dehydration/Hypervolemia - K+ Hypokalemia/Hyperkalemia - Cl�' Hyperchloremia/Hypochloremia
Purine and pyrimidineHyperuricemia - Lesch-Nyhan syndrome - Xanthinuria
PorphyrinAcute intermittent, Gunther's, Cutanea tarda, Erythropoietic, Hepatoerythropoietic, Hereditary copro-, Variegate
BilirubinUnconjugated (Lucey-Driscoll syndrome, Gilbert's syndrome, Crigler-Najjar syndrome) - Conjugated (Dubin-Johnson syndrome, Rotor syndrome)
GlycosaminoglycanMucopolysaccharidosis - 1:Hurler/Hunter - 3:Sanfilippo - 4:Morquio - 6:Maroteaux-Lamy - 7:Sly
GlycoproteinMucolipidosis - I-cell disease - Pseudo-Hurler polydystrophy - Aspartylglucosaminuria - Fucosidosis - Alpha-mannosidosis - Sialidosis
OtherAlpha 1-antitrypsin deficiency - Cystic fibrosis - Amyloidosis (Familial Mediterranean fever) - Acatalasia
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hyperammonemia". A list of authors is available in Wikipedia.
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