From Wikipedia, the free encyclopedia
Primary carnitine deficiency is a condition that prevents the body from using fats for energy, particularly during periods without food. Carnitine, a natural substance acquired mostly through diet, is used by cells to process fats and produce energy. People with primary carnitine deficiency have defective proteins called carnitine transporters, which bring carnitine into cells and prevent its escape from the body.
Typically, initial signs and symptoms of this disorder occur during infancy or early childhood and often include brain function abnormalities (encephalopathy); an enlarged, poorly pumping heart (cardiomyopathy); confusion; vomiting; muscle weakness; and low blood sugar (hypoglycemia). Serious complications such as heart failure, liver problems, coma, and sudden unexpected death are also a risk. Acute illness due to primary carnitine deficiency can be triggered by periods of fasting or illnesses such as viral infections, particularly when eating is reduced.
Primary carnitine deficiency is sometimes diagnosed in adults and is then thought to be less severe both in symptoms and life expectation. Treatment is usually done by supplementation of L-carnitine after assessing the severity of the deficiency after a muscular biopsy.
This condition is sometimes mistaken for Reye syndrome, a severe disorder that develops in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections.
On the average, primary carnitine deficiency affects 1 in every 40,000 live births in Japan and 1 in every 37,000 to 100,000 newborns in Australia. The incidence of this condition in other populations is unknown, but is probably similar to that reported for Japan.
Mutations in the SLC22A5 gene lead to the production of defective carnitine transporters. As a result of reduced transport function, carnitine is lost from the body and cells are not supplied with an adequate amount of carnitine. Without carnitine, fats cannot be processed correctly and are not converted into energy, which can lead to characteristic signs and symptoms of this disorder. This condition is inherited in an autosomal recessive pattern.
The current understanding of primary carnitine deficiency has been greatly influenced by the research of Doctors Susan C. Winter and Neil Buist. Dr. Winter was one of the first doctors in the United States to begin treating inborn errors of metabolism with intravenous carnitine.
This article incorporates public domain text from The U.S. National Library of Medicine
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Metabolic pathology / Inborn error of metabolism (E70-90, 270-279) |
| Amino acid |
Aromatic (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 |
| Carbohydrate |
Lactose 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 storage |
Sphingolipidoses/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) |
| Other lipid |
Lipoprotein/lipidemias: Hyperlipidemia - Hypercholesterolemia - Familial hypercholesterolemia - Xanthoma - Combined hyperlipidemia - Lecithin cholesterol acyltransferase deficiency - Tangier disease - Abetalipoproteinemia
Fatty acid: Adrenoleukodystrophy - Carnitine (Primary, I, II) |
| Mineral |
Cu 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 pyrimidine |
Hyperuricemia - Lesch-Nyhan syndrome - Xanthinuria |
| Porphyrin |
Acute intermittent, Gunther's, Cutanea tarda, Erythropoietic, Hepatoerythropoietic, Hereditary copro-, Variegate |
| Bilirubin |
Unconjugated (Gilbert's syndrome, Crigler-Najjar syndrome) - Conjugated (Dubin-Johnson syndrome, Rotor syndrome) |
| Glycosaminoglycan |
Mucopolysaccharidosis - 1:Hurler/Hunter - 3:Sanfilippo - 4:Morquio - 6:Maroteaux-Lamy - 7:Sly |
| Glycoprotein |
Mucolipidosis - I-cell disease - Pseudo-Hurler polydystrophy - Aspartylglucosaminuria - Fucosidosis - Alpha-mannosidosis - Sialidosis |
| Other |
Alpha 1-antitrypsin deficiency - Cystic fibrosis - Amyloidosis (Familial Mediterranean fever) - Acatalasia |