Assessment of plasma ammonia and glutamine concentrations in urea cycle disorders.

To analyze the association between ammonia and glutamine used for metabolic control in inherited urea cycle disorders (UCD) in a large series of patients.Paired plasma amino acid-ammonia data from 26 UCD patients were analyzed (n=921).Increased plasma glutamine values were consistently observed in UCD patients, despite normal plasma ammonia concentrations, especially for mitochondrial UCD.Further therapeutic efforts are probably needed to control increased glutamine values, considering their potentially neurotoxic effect.