Hiding in Plain Sight: A Case of Ornithine Transcarbamylase Deficiency Unmasked Post–Liver Transplantation

• Published in: American journal of transplantation Vol. 17; no. 5; pp. 1405 - 1408
• Main Authors: Ramanathan, M., Uppalapu, S., Patel, N. M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 01-05-2017
• Subjects: Brain Edema - enzymology; Brain Edema - etiology; clinical research/practice; donors and donation: donor evaluation; donors and donation: extended criteria; Humans; Hyperammonemia - enzymology; Hyperammonemia - etiology; Liver; liver allograft function/dysfunction; Liver Transplantation - adverse effects; liver transplantation/hepatology; Male; Metabolism; Middle Aged; Ornithine Carbamoyltransferase - metabolism; Ornithine Carbamoyltransferase Deficiency Disease - complications; Prognosis; Tissue Donors; Transplantation, Homologous; Transplants & implants; liver allograft function/dysfunction; donors and donation: extended criteria; donors and donation: donor evaluation; liver transplantation/hepatology; clinical research/practice
• ISSN: 1600-6135; 1600-6143
• DOI: 10.1111/ajt.14174

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.
The authors report the clinical course of a liver transplant recipient who ultimately died of cerebral edema due to unrecognized ornithine transcarbamylase deficiency in the donor liver and resultant severe hyperammonemia.