[Creatine deficiency syndromes].
BACKGROUND
Creatine deficiency syndromes are a newly described group of inborn errors of metabolism affecting creatine metabolism. Three diseases have been described: deficiency of arginine: glycine amidinotransferase (AGAT), deficiency of guanidinoacetate methyltransferase (GAMT) and creatine transporter defect (CRTR).


BACKGROUND
These syndromes are characterized by a depletion of creatine/phosphocreatine in the brain. Clinically, most of the patients develop a variable mental retardation and a severe speech delay associated with epilepsy, extra-pyramidal syndrome and behavior disturbances. These diseases are often diagnosed during infancy but a few adult cases have been reported recently. Diagnosis is established by measurement of guanidinoacetate and creatine in biologic fluids and in vivo proton magnetic resonance spectroscopy by the total lack of intra-cerebral creatine/phosphocreatine demonstrating. GAMT and AGAT deficiencies are treatable by oral creatine supplementation whereas patients with CRTR do not respond to the treatment.


CONCLUSIONS
Better knowledge of these syndromes is necessary to optimize diagnosis and patient management of these rare but potentially treatable disorders.
Cheillan
D
D
Service de Biochimie Pédiatrique, Hôpital Debrousse, 29, rue Soeur-Bouvier, 69322 Lyon, France. david.cheillan@chu-lyon.fr
Cognat
S
S
Vandenberghe
N
N
Des Portes
V
V
Vianey-Saban
C
C
D000579:Amidinotransferases / Q000235:genetics; D000818:Animals; D003401:Creatine / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D050937:Guanidinoacetate N-Methyltransferase; D006801:Humans; D026901:Membrane Transport Proteins / Q000378:metabolism; D008661:Metabolism, Inborn Errors / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism*; D008780:Methyltransferases / Q000235:genetics
D026901:Membrane Transport Proteins; C080679:creatine transporter; D008780:Methyltransferases; C494506:GAMT protein, human; D050937:Guanidinoacetate N-Methyltransferase; D000579:Amidinotransferases; C020681:glycine amidinotransferase; D003401:Creatine