HYPERAMMONEMIC COMA DUE TO PARENTERAL-NUTRITION IN A WOMAN WITH HETEROZYGOUS ORNITHINE TRANSCARBAMYLASE DEFICIENCY

Ornithine transcarbamylase deficiency is an X-linked disorder of the u rea cycle that can cause hyperammonemic encephalopathy in hemizygous m ales and heterozygous females. Affected females typically limit protei n intake in their diet. This case report describes a 36-year-old woman with ulcerative colitis who went into hyperammonemic coma after admin istration of total parenteral nutrition. A similar episode of coma had occurred 7 years earlier after she delivered a normal boy. Heterozygo us ornithine transcarbamylase deficiency was diagnosed based on a posi tive allopurinol tolerance test result after elevated revels of plasma glutamine and low plasma citrulline were detected. The protein load a ssociated with parenteral alimentation resulted in symptomatic express ion of this partial enzyme deficiency in this unique case. Partial orn ithine transcarbamylase deficiency must always be considered in adult women and men with hyperammonemia who have normal liver function test results.