Tyrosinemia

(medicine) An inborn metabolic disorder in which there is a deficiency of the enzyme p-hydroxyphenylpyruvic acid oxidase with abnormally high blood levels of tyrosine and sometimes methionine.

A genetic disorder of amino acid metabolism in which tyrosine acid accumulates in the blood and urine at abnormally high levels; seen primarily in infants born prematurely; may respond to a low-protein diet and the administration of synthetic amino acids.

An excess of tyrosine in the blood. Several different types with varying clinical features occur in humans. A syndrome of dermatitis and keratoconjunctivitis resembling tyrosinemia type II of humans (Richner–Hanhart syndrome) occurs in rats fed a diet high in tyrosine, in mink as an inherited disorder (called also pseudodistemper) and it has been reported in a dog.

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Tyrosinemia
Classification and external resources
Tyrosine
ICD-10	E70.2
ICD-9	270.2
OMIM	276700 276600 276710
DiseasesDB	13478 13486 29836
eMedicine	ped/2339
MeSH	[1]

Tyrosinemia (or "Tyrosinaemia") is an error of metabolism, usually inborn, in which the body cannot effectively break down the amino acid tyrosine. Symptoms include liver and kidney disturbances and mental retardation.

Most inborn forms of tyrosinemia produce hypertyrosinemia (high levels of tyrosine).^[1]

Contents 1 Types 2 Treatment 3 See also 4 References 5 External links

Types

Tyrosinemia is inherited in an autosomal recessive pattern.

There are three types of tyrosinemia, each with distinctive symptoms and caused by the deficiency of a different enzyme.

• Type I tyrosinemia
• Type II tyrosinemia
• Type III tyrosinemia

Treatment

Treatment varies depending on the specific type. A low protein diet may be required in the management of tyrosinemia. Recent experience with NTBC has shown to be very effective. The most effective treatment in patients with tyrosinemia type I seems to be full or partial liver transplant.

See also

• Alkaptonuria
• Inborn error of metabolism
• Ochronosis

References

1. ^ Charles Scriver, Beaudet, A.L., Valle, D., Sly, W.S., Vogelstein, B., Childs, B., Kinzler, K.W. (Accessed 2007). The Online Metabolic and Molecular Bases of Inherited Disease. Chapter 79. New York: McGraw-Hill.

External links

• University of Washington

v • d • e Inborn error of amino acid metabolism (E70-72, 270) K→acetyl-CoA Lysine/straight chain Glutaric acidemia type 1 · type 2 · Hyperlysinemia · Pipecolic acidemia · Saccharopinuria Leucine Maple syrup urine disease · Isovaleric acidemia · 3-Methylcrotonyl-CoA carboxylase deficiency · 3-hydroxy-3-methylglutaryl-CoA lyase deficiency Tryptophan Hypertryptophanemia G G→pyruvate→citrate Glycine Sarcosinemia · D-Glyceric acidemia · Glutathione synthetase deficiency Glycine→Creatine: GAMT deficiency G→glutamate→ α-ketoglutarate Histidine Carnosinemia · Histidinemia · Urocanic aciduria Proline Hyperprolinemia · Prolidase deficiency Glutamate/glutamine SSADHD G→propionyl-CoA→ succinyl-CoA Valine Maple syrup urine disease · Hypervalinemia · Isobutyryl-CoA dehydrogenase deficiency Isoleucine Maple syrup urine disease · Beta-ketothiolase deficiency · 2-Methylbutyryl-CoA dehydrogenase deficiency Methionine Hypermethioninemia · Homocystinuria · Cystathioninuria General BC/OA Propionic acidemia · Methylmalonic acidemia · Methylmalonyl-CoA mutase deficiency G→fumarate Phenylalanine/tyrosine Phenylketonuria Tetrahydrobiopterin deficiency · 6-Pyruvoyltetrahydropterin synthase deficiency Tyrosinemia Type II tyrosinemia · Type III tyrosinemia/Hawkinsinuria · Alkaptonuria/Ochronosis · Type I tyrosinemia Tyrosine→Melanin Albinism: Ocular albinism (1) · Oculocutaneous albinism (Hermansky-Pudlak syndrome) · Waardenburg syndrome G→oxaloacetate Urea cycle/Hyperammonemia (arginine, aspartate) N-Acetylglutamate synthase deficiency · Carbamoyl phosphate synthetase I deficiency · Ornithine transcarbamylase deficiency/translocase deficiency · Citrullinemia · Argininosuccinic aciduria · Argininemia Transport/ IE of RTT Solute carrier family: Cystinuria · Hartnup disease · Lysinuric protein intolerance · Iminoglycinuria other/general/unknown: Oculocerebrorenal syndrome · Fanconi syndrome · Cystinosis Other Trimethylaminuria · 2-Hydroxyglutaric aciduria · Fumarase deficiency see also Amino acid metabolism enzymes, intermediates see also Urea cycle enzymes, intermediates

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