Argininosuccinic aciduria: metabolic studies and effects of treatment with keto-analogues of essential amino acids.

A 22 years old female with the late-onset of argininosuccinic aciduria was successfully treated for 5 months with a mixture of essential amino acids and their keto-analogues. There was a marked change in plasma ammonia, plasma amino acids and argininosuccinic acid excretion. A long term anabolic response was reflected by an increase of total serum proteins and serum albumin by about 1 g/dl during the first 5 months of treatment. There was a striking improvement in the patient's seizure disorder following institution of the keto-analogue therapy.