title: Laboratory evaluation of urea cycle disorders.
abstract: The urea cycle disorders (UCDs) represent a group of inherited metabolic diseases with hyperammonemia as the primary laboratory abnormality. Affected individuals may become comatose or die if not treated rapidly. Diagnosis of a UCD requires a high index of suspicion and judicious use of the laboratory. It is important to rule out other conditions causing hyperammonemia that may require different treatment. The astute clinician may suspect a specific UCD in the appropriate clinical setting, but only laboratory results can confirm a specific diagnosis. The importance of the laboratory in helping the clinician to differentiate among various causes of hyperammonemia, in confirming a specific UCD, in carrier testing, and in prenatal diagnostic testing is highlighted in this review.
authors.affiliation: Metabolic Clinic, Child Development and Rehabilitation Center, Doernbecher Children's Hospital, Oregon Health Sciences University, Portland, Oregon 97201, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Steiner
authors.forename: S D
authors.initials: SD
authors.lastname: Cederbaum
mesh_terms: D000465:Algorithms; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis*; D002956:Citrulline / Q000378:metabolism; D004252:DNA Mutational Analysis; D006801:Humans; D022124:Hyperammonemia / Q000175:diagnosis* / Q000209:etiology; D009963:Orotic Acid / Q000652:urine; D014508:Urea / Q000378:metabolism*
chemical_list: D002956:Citrulline; D009963:Orotic Acid; D014508:Urea