European Journal of Pediatrics

, Volume 134, Issue 2, pp 109–113

Diagnostic value of orotic acid excretion in heritable disorders of the urea cycle and in hyperammonemia due to organic acidurias

  • C. Bachmann
  • J. P. Colombo
Original Investigations

DOI: 10.1007/BF01846026

Cite this article as:
Bachmann, C. & Colombo, J.P. Eur J Pediatr (1980) 134: 109. doi:10.1007/BF01846026


Orotic acid excretion in urine is increased in ornithine transcarbamylase deficiency, citrullinemia and argininemia; it is barely increased in argininosuccinic aciduria and normal in carbamylphosphate synthetase deficiency and in hyperammonemia due to organic aciduria. The determination of orotic acid excretion is useful in differentiating the causes of hyperammonemia and reduces the need for enzymatic assays on tissue biopsies for decisions on therapy. The data indicate that orotic acid does not merely reflect ammonia concentration in plasma, but depends on carbamylphosphate concentration. Arginine could play a key role in the regulation of ammonia detoxication.

Key words

Orotic acid Urea cycle Metabolism, inborn errors Hyperammonemia Organic aciduria 

Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • C. Bachmann
    • 1
  • J. P. Colombo
    • 1
  1. 1.Dept. Clin. Chemistry, InselspitalUniversity of BerneBerneSwitzerland

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