Guanidinoacetate Methyltransferase Deficiency (GAMT Deficiency)

Guanidinoacetate Methyltransferase Deficiency (Creatine-Deficiency-Syndrome) is a rare autosomal recessive disease caused by a mutation in the GAMT gene which codes for guanidinoacetate N-methyltransferase. A deficiency in this enzyme results in accumulation of 3-methylglutaconic acid in urine; guanidoacetic acid in urine and serum. Decreased concentrations of creatine are found in serum and urine; and creatinine in plasma, spinal fluid, and urine. Symptoms, which present at birth, include failure to thrive, mental and motor retardation, hyoptonia, and seizures. Treatment includes arginine-restricted diet, sodium benzoate, and L-ornithine hydrochlorate.

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  1. OMIM: Entry 612736
  2. Uniprot: Q14353
  3. Engelke, U., van der Graaf, M., Heerschap, A., Hoenderop, S., Moolenaar, S., Morava, E., Wevers, R. (2007). Handbook of 1H-NMR spectroscopy in inborn errors of metabolism: body fluid NMR spectroscopy and in vivo MR spectroscopy (pp 53) (2nd ed). Heilbronn: SPS Verlagsgesellschaft
  4. Caldeira Araujo H, Smit W, Verhoeven NM, Salomons GS, Silva S, Vasconcelos R, Tomas H, Tavares de Almeida I, Jakobs C, Duran M: Guanidinoacetate methyltransferase deficiency identified in adults and a child with mental retardation. Am J Med Genet A. 2005 Mar 1;133A(2):122-7. Pubmed
  5. Stockler S, Isbrandt D, Hanefeld F, Schmidt B, von Figura K: Guanidinoacetate methyltransferase deficiency: the first inborn error of creatine metabolism in man. Am J Hum Genet. 1996 May;58(5):914-22. Pubmed
  6. Schulze A: Creatine deficiency syndromes. Mol Cell Biochem. 2003 Feb;244(1-2):143-50. Pubmed