Table 1.

Common patterns of plasma amino acid and orotic acid disturbance by disorder.

Disorder	Amino acid abnormalities	Urine orotic acid
Ornithine transcarbamylase deficiency	Decreased citrulline, elevated glutamine, elevated alanine, decreased arginine10,11	Markedly elevated
N-acetylglutamate synthetase deficiency	Decreased citrulline, elevated glutamine, elevated alanine11	Normal
Carbamoyl phosphate synthetase deficiency	Decreased citrulline, elevated glutamine, elevated alanine, decreased arginine10,11	Normal
Arginosuccinic acid synthetase deficiency	Markedly elevated citrulline, decreased arginine10–12	Elevated
Arginosuccinic acid lyase deficiency	Elevated citrulline, elevated arginosuccinic acid, decreased arginine 11,13	Elevated
Arginase deficiency	Elevated arginine11	Elevated
Sepsis	Elevated aromatic and sulfur containing amino acids, decreased branched-chain amino acids14	Normal
Hepatic dysfunction	Elevated tyrosine and methionine, decreased branched-chain amino acids15	Normal