title: Hiding in Plain Sight: A Case of Ornithine Transcarbamylase Deficiency Unmasked Post-Liver Transplantation.
abstract: Ornithine transcarbamylase deficiency represents the most common inherited defect of the urea cycle. This enzyme, predominantly found in the liver, plays a crucial role in recycling free ammonia, with deficiencies often leading to fatal complications. Here, we present the case of a 63-year-old man with alcoholic cirrhosis who underwent orthotopic liver transplantation, gradual worsening of his mental status, and progressive elevation of ammonia levels. Liver allograft function was deemed normal, raising concern for a donor-derived metabolic disorder of the urea cycle. Evaluation of the donor patient's blood revealed that the donor was heterozygous for the OTC gene. Posttransplantation changes in mental status should prompt a clinician to consider the most likely causes; however, once these have been ruled out, it is important to consider the less common causes of metabolic derangements. The rarity of these disorders makes expertise of diagnosis, standardization of evaluation, and treatment strategies challenging.
authors.affiliation: Department of Internal Medicine, Banner University Medicine Center Phoenix, Phoenix, AZ.|Banner University Medicine Center Phoenix, Phoenix, AZ.|Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, AZ.
authors.forename: M
authors.initials: M
authors.lastname: Ramanathan
authors.affiliation: Banner University Medicine Center Phoenix, Phoenix, AZ.|Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, AZ.|Department of Pulmonary and Critical Care Medicine, Banner University Medicine Center Phoenix, Phoenix, AZ.
authors.forename: S
authors.initials: S
authors.lastname: Uppalapu
authors.affiliation: Banner University Medicine Center Phoenix, Phoenix, AZ.|Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, AZ.|Transplant and Advanced Liver Disease Center, Banner University Medicine Center Phoenix, Phoenix, AZ.
authors.forename: N M
authors.initials: NM
authors.lastname: Patel
mesh_terms: D001929:Brain Edema / Q000201:enzymology / Q000209:etiology*; D006801:Humans; D022124:Hyperammonemia / Q000201:enzymology / Q000209:etiology*; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009954:Ornithine Carbamoyltransferase / Q000378:metabolism*; D020163:Ornithine Carbamoyltransferase Deficiency Disease / Q000150:complications*; D011379:Prognosis; D014019:Tissue Donors; D014184:Transplantation, Homologous
chemical_list: D009954:Ornithine Carbamoyltransferase
keywords: clinical research/practice; donors and donation: donor evaluation; donors and donation: extended criteria; liver allograft function/dysfunction; liver transplantation/hepatology