Journal of Endocrinology and Metabolism, ISSN 1923-2861 print, 1923-287X online, Open Access
Article copyright, the authors; Journal compilation copyright, J Endocrinol Metab and Elmer Press Inc
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Case Report

Volume 4, Number 1-2, April 2014, pages 32-35

A Novel Description of Increased Urinary Orotic Acid Excretion in Pediatric Trauma


Figure 1.
Figure 1. Orotic acid in relation to several metabolic pathways: the urea cycle, the de novopyrimidine synthesis pathway and the purine salvage pathway. Enzymes shown in bold, red: ATC, aspartate transcarbamylase; DHO, dihydroorotase; DHODH, dihydroorotate dehydrogenase; HPRT, hypoxanthine-guanine phosphoribosyl transferase (deficiency of this enzyme results in Lesh-Nyhan syndrome); OTC, ornithine transcarbamylase; PNP, purine nucleoside phosphorylase; and UMPS, uridine monophosphate synthase. Intermediates, substrates, or products: ARG, arginine; ASA, argininosuccinic acid; ASP; aspartic acid; CIT, citrulline; CP, carbamyl phosphate; GLN, glutamine; GMP; guanosine 5’-monophosphate, IMP; inosine 5’-monophosphate; ORN, ornithine; PPi, pyrophosphate; and PRPP, phosphoribosyl pyrophosphate.


Table 1. Differential Diagnosis for Urinary Orotic Acid Excretion
Urea cycle disorders [2]
  Ornithine transcarbamylase (OTC) deficiency
  Argininosuccinic aciduria
  Arginase deficiency
Pyrimidine and pyrimidine metabolism disorders
  Uridine monophosphate synthase deficiency (UMPS, hereditary orotic aciduria) [4, 5]
    UMPS, type I
    UMPS, type II
    Hereditary orotic aciduria without megaloblastic anemia (OAWA)
  Purine nucleoside phosphorylase (PNP) deficiency [5, 6]
Drugs (via inhibition of orotidine-5'-monophosphate decarboxylase) [12]
Severe Traumatic injuries
  Motor vehicle accidents, accidental falls, and/or crush injuries [13]
  Multiple bone fractures, head injuries, and/or extensive soft-tissue damage [13]
  Gunshot wounds to the abdomen, chest and face [13]
  Sepsis and severe abdominal trauma - abdominal compartment syndrome (this report)
  Non-accidental trauma, child abuse and/or penetrating injuries (this report)
Other disorders/syndromes
  Lysinuric protein intolerance [7]
  Rett syndrome [8]
  Reye syndrome [9]
  Lesch-Nyhan syndrome [10]
  Pervasive developmental delay (PPD) [11]