title: Liver Transplantation for Urea Cycle Disorders: Analysis of the United Network for Organ Sharing Database.
abstract: BACKGROUND
  Urea cycle disorders (UCD) are caused by rare inherited defects in the urea cycle enzymes leading to diminished ability to convert ammonia to urea in the liver. The resulting excess of circulating ammonia can lead to central nervous system toxicity and irreversible neurologic damage. Most cases are identified in children. However, UCDs can also be diagnosed in adulthood, and liver transplant is occasionally required.
  
  
  METHODS
  We examined the UNOS database to evaluate outcomes in adult and pediatric patients who underwent liver transplant as treatment for a UCD. We identified 265 pediatric and 13 adult patients who underwent liver transplant for a UCD between 1987 and 2010.
  
  
  RESULTS
  The majority (68%) of these patients were transplanted before age 5 years. Ornithine transcarbamylase (OTC) deficiency was the most common UCD in both adults and children who underwent transplant. UCD patients who underwent liver transplant were younger, more likely to be male (67%), had lower pediatric end-stage liver disease/model for end-stage liver disease scores, and were more likely to be Caucasian or Asian compared with all other patients transplanted during the same time period. UCD patients did not have an increased utilization of living donor transplantation in this US cohort. Univariate and multivariate risk factor analyses were performed and did not reveal any significant factors that were predictive of post-transplant death or graft loss.
  
  
  CONCLUSIONS
  Excellent outcomes were seen in both children and adults with UCDs who underwent transplant with overall 1-, 5-, and 10-year survivals of 93%, 89%, and 87%, respectively.
authors.affiliation: University of Washington, Division of Gastroenetrology and Hepatology, Seattle, Washington, USA.
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.affiliation: University of Washington, Department of Surgery, Seattle, Washington, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Rayhill
authors.affiliation: Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: E K
authors.initials: EK
authors.lastname: Hsu
authors.affiliation: University of Washington, Division of Gastroenetrology and Hepatology, Seattle, Washington, USA. Electronic address: clandis@medicine.washington.edu.
authors.forename: C S
authors.initials: CS
authors.lastname: Landis
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D058625:End Stage Liver Disease / Q000150:complications* / Q000601:surgery*; D005260:Female; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D014481:United States; D056806:Urea Cycle Disorders, Inborn / Q000150:complications* / Q000601:surgery; D055815:Young Adult