Guanidinoacetate methyltransferase deficiency: the first inborn error of creatine metabolism in man.
In two children with an accumulation of guanidinoacetate in brain and a deficiency of creatine in blood, a severe deficiency of guanidinoacetate methyltransferase (GAMT) activity was detected in the liver. Two mutant GAMT alleles were identified that carried a single base substitution within a 5' splice site or a 13-nt insertion and gave rise to four mutant transcripts. Three of the transcripts encode truncated polypeptides that lack a residue known to be critical for catalytic activity of GAMT. Deficiency of GAMT is the first inborn error of creatine metabolism. It causes a severe developmental delay and extrapyramidal symptoms in early infancy and is treatable by oral substitution with creatine.
Stöckler
S
S
Pediatric Nerology, University Children's Hospital Göttingen, Germany.
Isbrandt
D
D
Hanefeld
F
F
Schmidt
B
B
von Figura
K
K
D000483:Alleles; D001483:Base Sequence; D002675:Child, Preschool; D003401:Creatine / Q000378:metabolism*; D005260:Female; D050937:Guanidinoacetate N-Methyltransferase; D006801:Humans; D007223:Infant; D008297:Male; D008661:Metabolism, Inborn Errors / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008780:Methyltransferases / Q000172:deficiency* / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation
D008780:Methyltransferases; C494506:GAMT protein, human; D050937:Guanidinoacetate N-Methyltransferase; D003401:Creatine