Creatine deficiency in the brain: a new, treatable inborn error of metabolism

Pediatr Res. 1994 Sep;36(3):409-13. doi: 10.1203/00006450-199409000-00023.


In a patient with extrapyramidal movement disorder and extremely low creatinine concentrations in serum and urine, in vivo proton magnetic resonance spectroscopy disclosed a generalized depletion of creatinine in the brain. Oral substitution of arginine, a substrate for creatine synthesis, resulted in an increase of brain guanidinoacetate as the immediate precursor of creatine but did not elevate cerebral creatine levels. In contrast, oral substitution of creatine-monohydrate led to a significant increase of brain creatine, a decrease of brain guanidinoacetate, and a normalization of creatinine in serum and urine. Phosphorus magnetic resonance spectroscopy of the brain revealed no detectable creatine-phosphate before oral substitution of creatine and a significant increase afterward. Partial restoration of cerebral creatine concentrations was accompanied by improvement of the patient's neurologic symptoms. This is the first report of a patient with complete creatine deficiency in the brain. Magnetic resonance spectroscopy during arginine and creatine treatment point to an inborn error of creatine biosynthesis at the level of guanidinoacetete-methyltransferase.

Publication types

  • Case Reports

MeSH terms

  • Arginine / therapeutic use
  • Brain / metabolism*
  • Creatine / deficiency*
  • Creatine / therapeutic use
  • Humans
  • Infant
  • Magnetic Resonance Spectroscopy / methods
  • Male
  • Metabolism, Inborn Errors* / drug therapy
  • Phosphocreatine / deficiency*


  • Phosphocreatine
  • Arginine
  • Creatine