Argininosuccinic aciduria

# Overview
Argininosuccinic aciduria is an inherited disorder that causes ammonia to accumulate in the blood. Ammonia is toxic, especially to the nervous system, and argininosuccinic aciduria usually becomes evident in the first few days of life.
An infant with argininosuccinic aciduria may seem lethargic or be unwilling to eat, have poorly-controlled breathing rate or body temperature, experience seizures or unusual body movements, or go into a coma. Complications from argininosuccinic aciduria may include developmental delay and mental retardation. Progressive liver damage, skin lesions, and brittle hair may also be seen. Immediate treatment and lifelong management (following a strict diet and using appropriate supplements) may prevent many of these complications.
Occasionally, an individual may inherit a mild form of the disorder in which ammonia accumulates in the bloodstream only during periods of illness or other stress.

# Historical Perspective

# Classification

# Pathophysiology

## Genetics
Mutations in the ASL gene cause argininosuccinic aciduria. Argininosuccinic aciduria belongs to a class of genetic diseases called urea cycle disorders. The urea cycle is a sequence of reactions in the cells of the liver. It processes excess nitrogen, generated when protein is used by the body, to make a compound called urea that is excreted by the kidneys.
In argininosuccinic aciduria, the enzyme that starts a specific reaction within the urea cycle is damaged or missing. The urea cycle cannot proceed normally, and nitrogen accumulates in the bloodstream in the form of ammonia.
Ammonia is especially damaging to the nervous system, so argininosuccinic aciduria causes neurological problems as well as eventual damage to the liver.
This condition is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder.

# Causes

# Differentiating Argininosuccinic aciduria from Other Diseases

# Epidemiology and Demographics
Argininosuccinic aciduria occurs in approximately 1 in 70,000 live births.

# See Sources
- Kleijer WJ, Garritsen VH, Linnebank M, Mooyer P, Huijmans JG, Mustonen A, Simola KO, Arslan-Kirchner M, Battini R, Briones P, Cardo E, Mandel H, Tschiedel E, Wanders RJ, Koch HG (2002). "Clinical, enzymatic, and molecular genetic characterization of a biochemical variant type of argininosuccinic aciduria: prenatal and postnatal diagnosis in five unrelated families". J Inherit Metab Dis. 25 (5): 399410.CS1 maint: Multiple names: authors list (link) .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em} PMID 12408190
- Lee B, Goss J (2001). "Long-term correction of urea cycle disorders". J Pediatr. 138 (1 Suppl): S6271. PMID 11148551
- Reid Sutton V, Pan Y, Davis EC, Craigen WJ (2003). "A mouse model of argininosuccinic aciduria: biochemical characterization". Mol Genet Metab. 78 (1): 116.CS1 maint: Multiple names: authors list (link)  PMID 12559843
- Scaglia F, Brunetti-Pierri N, Kleppe S, Marini J, Carter S, Garlick P, Jahoor F, O'Brien W, Lee B (2004). "Clinical consequences of urea cycle enzyme deficiencies and potential links to arginine and nitric oxide metabolism". J Nutr. 134 (10 Suppl): 2775S2782S, discussion 2796S-2797S.CS1 maint: Multiple names: authors list (link)  PMID 15465784 Full text
- Stadler S, Gempel K, Bieger I, Pontz BF, Gerbitz KD, Bauer MF, Hofmann S (2001). "Detection of neonatal argininosuccinate lyase deficiency by serum tandem mass spectrometry". J Inherit Metab Dis. 24 (3): 3708.CS1 maint: Multiple names: authors list (link)  PMID 11486903
- Wilcken B, Smith A, Brown DA (1980). "Urine screening for aminoacidopathies: is it beneficial? Results of a long-term follow-up of cases detected bny screening one million babies". J Pediatr. 97 (3): 4927.CS1 maint: Multiple names: authors list (link)  PMID 7411317