The role of orthotopic liver transplantation in the treatment of ornithinetranscarbamylase deficiency

The purpose of this study was to combine our clinical experience with a rev iew of the literature to determine the value of orthotopic liver transplant ation in the treatment of both boys and girls with ornithine transcarbamyla se deficiency, Three boys younger than I year of age with symptomatic ornit hine transcarbamylase deficiency (median age, 116 days; range, 40 to 223 da ys) underwent orthotopic liver transplantation. The patients' growth, devel opmental progress, ammonia levels, and amino acid levels were analyzed pre- and post-liver transplantation. The clinical courses of the respective pat ients and the treatment modalities used were compared with published report s from 1978 through 1997, The median follow-up period in these 3 patients w as 3.2 years (range, 9 months to 5.2 years). Orthotopic liver transplantati on restored normal urea production and stabilized ammonia levels within 24 hours of surgery (median serum ammonia level 24 hours post-liver replacemen t, 43 mu mol/L; range, 30 to 66 mu mol/L). After liver replacement, arginin e synthesis was normalized; however, plasma citrulline levels remained less than normal in all patients, Linear growth was evaluated in all 3 patients at the time of the most recent follow-up; median z scores for patient heig ht and weight were -2.16 and -1.16, respectively, Standardized intelligence tests showed that 2 of the 3 patients continue to perform at age-appropria te levels, The third child was developmentally delayed pretransplantation a t 4 months of age on presentation and continues to perform in a below-avera ge fashion, Orthotopic liver transplantation results in the restoration of normal urea production and serum ammonia levels in the boy suffering from s ymptomatic ornithine transcarbamylase deficiency, Serum arginine, but not c itrulline, levels are normalized, probably because of the persistent intest inal mucosa defect. Patient growth is similar to that in infants undergoing liver transplantation for other causes. When liver transplantation is perf ormed before cognitive impairment occurs, intellectual development is norma l, because the risk of additional episodes of hyperammonemia is elevated. C opyright (C) 1998 by the American Association for the Study of Liver Diseas es.