title: A case of transient neonatal citrullinemia.
abstract: A male infant with transient citrullinemia is described. Initially, he was found to have hypertyrosinemia and hypermethioninemia upon routine neonatal screening for inborn errors of metabolism performed at 4 days of age and was revealed to have citrullinemia upon detailed examination of plasma amino acids. At 30 days of age, the plasma citrulline concentration was 13 mg/dl (normal, less than 0.8). In addition, the citrulline concentrations in the urine and cerebrospinal fluid (CSF) were markedly elevated. The blood ammonia and the CSF ammonia concentrations (300 micrograms/dl and 59 micrograms/dl, respectively) were also increased, but the infant showed no symptoms. Dietary protein intake was restricted to 2 g/kg/day, resulting in normalization of plasma citrulline and blood ammonia concentrations by 2 months of age. At 12 months of age, the infant was given a regular diet, and his physical and mental development was normal. 14C-citrulline incorporation into trichloroacetic acid (TCA)-precipitable material was normal in the fibroblasts. This report describes the first case in the literature of transient neonatal citrullinemia.
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis; D000641:Ammonia / Q000097:blood; D002956:Citrulline / Q000097:blood*; D003937:Diagnosis, Differential; D004044:Dietary Proteins; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male
chemical_list: D004044:Dietary Proteins; D002956:Citrulline; D000641:Ammonia