[8] Human Genes: ZFX, zincfinger protein, X-linked; ZFY, zinc finger protein, Y-linked; GJB2, gap junction protein beta 2; OTC, ornithine
carbamoyltransferase.
Ornithine transcarbamylase (OTC) deficiency (also referred to as ornithine
carbamoyltransferase deficiency) is an Xlinked proximal urea cycle disorder that results in a spectrum of severe neonatal-onset disease in boys, rarely in girls, and a milder adult-onset presentation.
Additionally, IFM demonstrated higher protein import rates for the precursors to malate dehydrogenase and ornithine
carbamoyltransferase [60].
The majority of these expressed proteins were involved in glycolysis (enolase, fructose-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, L-lactate dehydrogenase, 6-phosphofructokinase, glucose-6-phosphate isomerase, phosphoglycerate kinase, phosphopyruvate hydratase, pyruvate kinase, triosephosphate isomerase, and 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase) and the remaining proteins were involved in fer-mentation (alcohol-acetaldehyde dehydrogenase, formate ace-tyltransferase, and pyruvate-formate lyase), the pentose phosphate pathway (6-phosphogluconate dehydrogenase [decarboxylating]), pyruvate decarboxylation (pyruvate dehydrogenase complex E2 component), and the urea cycle (ornithine
carbamoyltransferase).
This hypothesis is supported by expression of arcA, arcB, arcC, and arcD, genes predicted to encode an arginine deiminase, an ornithine
carbamoyltransferase, a carbamate kinase, and an arginine/ornithine antiporter, respectively (Table 3).
Nearly all of the proteins altered in significant amounts were identified as enzymes associated with important metabolic pathways, such as alcohol dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Xaa-His dipeptidase, ornithine
carbamoyltransferase, putative O-acetylserine lyase, enolase (2-phosphoglycerate dehydratase), fructose-bisphosphate aldolase, and cysteine synthase.
This dramatic case stumped physicians until the woman's blood revealed a telltale high level of ammonia, a diagnostic clue suggesting a rare, inherited disorder called ornithine
carbamoyltransferase deficiency.
One of the girls who died after dermal exposure was partially deficient in the enzyme ornithine
carbamoyltransferase (3); DEET may interfere with the urea cycle metabolic pathway (10).