Argininemia: Report of a New Case and Mechanisms of Orotic Aciduria and Hyperammonemia

Abstract

Arqininemia is a rare inborn error of ureagenesis due to a deficiency of arginase activity (Terheggen et al., 1969; Terheggen, et al., 1970a; Terheggen et al., 1970b; Terheggen et al., 1975; Cederbaum et al., 1976; Snyderman et al., 1977; Cederbaum et al., 1977; Michels and Beaudet, 1978; Snyderman et al., 1979). Despite the apparent defect in enzyme activity, hyperammonemia is only intermittently observed in this disease, unlike other enzymopathies of the urea cycle. Increase in orotic acid excretion is also another biochemical characteristic of this disease (Snyderman et al., 1977; Bachmann and Colombo, 1980). However, the mechanisms of hy-perammonemia and orotic aciduria have not been thoroughly explained. The purpose of this communication is to describe clinical features at 2 hours of testing. Concentration of arginine was elevated also in cerebrospinal fluid (1.91 mg/dl, normal range; 0.15–0.55 mg/dl), orotic aciduria.