Argininosuccinic aciduria, Detection

Millington DS, Maltby DA, Roe CR (1986) Rapid detection of argininosuccinic aciduria and citrullinuria by fast atom bombardment and tandem mass spectrometry. Clin Chim Acta 155 173-178... 

Using this isotope labeling approach, metabolites in human plasma have been quantified (38) and altered metabolites have been detected in urine that are due to metabolic disorders such as tyrosinemia type II, argininosuccinic aciduria, homocystinuria, and phenylketonuria (20). Most recently, a smart isotope tag, 15N-cholamine, has been developed for effective detection of the same metabolites using both NMR and MS methods. This approach maximizes the combined strengths of two powerful analytical techniques for a variety of metabolomics applications. 15N-cholamine possesses dual characteristics an NMR-sensitive heteronuclear isotope with good chemical shift dispersion and a permanent charge that improves MS sensitivity (48). 

Liver and Red Cell. The identification by Westall (W3, W4) of the amino acid excreted in large amounts as an intermediate in the urea cycle led him to postulate a deficiency of argininbsuccinate lyase in this condition. He confirmed this in the red cells of two affected children. In all other cases of argininosuccinic aciduria in which this assay has been performed, no enzyme activity has been detected in the red cells... 

Inheritance o/ Argininosuccinic Aciduria and Detection of the Heterozygote State... 

Vidailhet et al. (VI) assayed all five enzymes involved in the urea cycle, and found no detectable activity of argininosuccinate synthetase, whereas the other enzymes were present in normal activity (Table 9). It is of interest that an appreciable synthetase activity was detectable in the kidney tissue in their patient, at a level of about 20% of that found in normal liver, despite its absence in the patient s liver (L4). This observation is similar to that of Colombo and Baumgartner (C8), who found argininosuccinate lyase in the kidney of their child with argininosuccinic aciduria, in spite of its absence from the liver. The question is again raised whether it is possible thus to account for the production of urea in these cases. However, since arginase is not present in the kidney, the arginine formed would have to be transported to the liver... 

Detection of Argininosuccinic Aciduria by Gas Chromatography Clin. Chim. Acta 23(1) 27-31 (1969) CA 70 34871V... 

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