title: Ornithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery.
abstract: BACKGROUND
  Neurological complications following bariatric surgery are rare. Whereas nutritional deficiencies are the most common cause of neurological symptoms, the unmasking of previously subclinical metabolic disorders can also lead to significant morbidity.
  
  
  OBJECTIVE
  To characterize the clinical presentation, serum biochemical fluctuations, and functional enzymatic analysis of a case of functional ornithine transcarbamylase deficiency unmasked by a dietary change following bariatric surgery.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Tertiary referral center, hospital (inpatient) setting.
  
  
  METHODS
  A 29-year-old woman who presented with intermittent encephalopathy associated with recurrent hyperammonemia.
  
  
  METHODS
  Clinical, biochemical, and mutational studies.
  
  
  RESULTS
  The pattern of intermittent hyperammonemia and encephalopathy following oral and parenteral nutrition suggested a urea cycle abnormality. Functional enzymatic assay results showed markedly reduced ornithine transcarbamylase activity in the absence of known coding mutations.
  
  
  CONCLUSIONS
  Previously asymptomatic ornithine transcarbamylase deficiency should be suspected in adult patients who develop recurrent hyperammonemia and encephalopathy following bariatric surgery.
authors.affiliation: Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Hu
authors.forename: Orhun H
authors.initials: OH
authors.lastname: Kantarci
authors.forename: J Lawrence
authors.initials: JL
authors.lastname: Merritt
authors.forename: Pamela
authors.initials: P
authors.lastname: McGrann
authors.forename: P James B
authors.initials: PJ
authors.lastname: Dyck
authors.forename: Claudia F
authors.initials: CF
authors.lastname: Lucchinetti
authors.forename: Maja
authors.initials: M
authors.lastname: Tippmann-Peikert
mesh_terms: D000328:Adult; D050110:Bariatric Surgery / Q000009:adverse effects*; D001927:Brain Diseases / Q000209:etiology*; D005260:Female; D006801:Humans; D009767:Obesity, Morbid / Q000601:surgery; D020163:Ornithine Carbamoyltransferase Deficiency Disease / Q000209:etiology*; D011183:Postoperative Complications; D013997:Time Factors