argininosuccinicaciduria

A disorder of urea cycle due to a deficiency of argininosuccinate lyase; characterized by physical and mental retardation, epilepsy, ataxia, liver disease, friable, tufted hair, and excessive urinary excretion of argininosuccinic acid. Autosomal recessive inheritance, caused by mutation in argininosuccinate lyase gene (ASL) on chromosome 7q.

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ar·gi·ni·no·suc·cin·ic·ac·id·uria (ahr″jĭ-ne″no-suk-sin″ik-as″ĭ-duґre-ə) 1. an autosomal recessive aminoacidopathy caused by mutations in the ASL gene (locus: 7cen-q11.2), which encodes argininosuccinate lyase, characterized by urinary excretion of argininosuccinic acid with hyperammonemia, argininosuccinicacidemia, and hypercitrullinemia. Neonatal and late onset forms exist, and clinical findings, which vary widely in severity, include mental retardation, seizures, ataxia, hepatomegaly, and friable hair. Called also argininosuccinase or argininosuccinate lyase deficiency. 2. excretion of argininosuccinic acid in the urine.