Late onset argininosuccinic aciduria in a paranoid retardate

Abstract

Argininosuccinic aciduria (ASA-uria) is an autosomal recessive disorder of the urea cycle caused by a deficiency in the enzyme L-argininosuccinic acid lyase (EC 4.3.2. I) (W~ser 1983), causing argininosuccinic acid (ASA) to accumulate in the body fluids. Hyperammonemi_~_ is ~ common finding. The incidence of the disorder varies from 1:70,000 1:250,000 births (Walser 1983). The clinical picture is variable, including a fetal and a neonatal type with massive ASA-uria, hyperammonemia and severe clinical symptoms, often leading to early death, a subacute type with failure to thrive, seizures and psychomotor retardation, carrying a lower mortality, and a late-onset type with neurological abnormalities and varying degrees of mental retardation not entailing increased mortality (Walser 1983). We report here on clinical and biochemical findings in a 63-year-old man with mental retardation and paranoid psychosis who was suffering from late onset ASA-~a.