Amino Acid Disorders |
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| Disease Name | Argininosuccinyl-CoA lyase deficiency |
| Alternate name(s) | Argininosuccinase deficiency, Argininosuccinic aciduria, Argininosuccinic acid lyase deficiency, ASL deficiency |
| Acronym | ASAL |
| Disease Classification | Amino Acid Disorder |
| Variants | Yes |
| Variant name | Late onset form |
| Symptom onset | Neonatal onset is typical, although later-onset may occur. |
| Symptoms | Anorexia, vomiting, lethargy, seizures and coma possibly leading to death. |
| Natural history without treatment | Mental and physical retardation due to hyperammonemia, cyclic vomiting, seizures, cerebral edema and trichorrhexis nodosa. Coma and death possible. |
| Natural history with treatment | Normal mental and physical development is possible if treatment is initiated before hyperammonemic crisis. |
| Treatment | Protein restricted diet, arginine supplementation to help complete the urea cycle, essential amino acid supplementation, ammonia scavenging drugs in some cases and supplemental carnitine if patient has a secondary deficiency. |
| Other | Enzyme is genetically heterogeneous and patients may present in infancy/childhood with MR or seizures. |
| Physical phenotype | Trichorrhexis nodosa (short, dry, brittle hair) in older patients. |
| Inheritance | Autosomal recessive |
| General population incidence | 1:70,000 |
| Ethnic differences | No |
| Population | N/A |
| Ethnic incidence | N/A |
| Enzyme location | Erythrocytes, liver and fibroblasts |
| Enzyme Function | Catalyzes the conversion of argininosuccinate to fumurate and arginine as part of the urea cycle. |
| Missing Enzyme | Argininosuccinate lyase |
| Metabolite changes | Hyperammonemia |
| Gene | ASL |
| Gene location | 7q11.2 |
| DNA testing available | No |
| DNA testing detail | No common mutation known. More that 25 mutations detected. |
| Prenatal testing | Enzyme assay in cultured amniocytes. DNA possible if mutations known. Analyte testing of amniocytes. |
| MS/MS Profile | Citrulline is elevated, may show elevated argininosuccinic peak. |
| OMIM Link | http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=207900 |
| Genetests Link | www.genetests.org |
| Support Group |
National Urea Cycle Disorders Foundation http://www.nucdf.org/ National Coalition for PKU and Allied Disorders http://www.pku-allieddisorders.org/ Children Living with Inherited Metabolic Diseases http://www.climb.org.uk/ |
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