GATM gene
glycine amidinotransferase
The GATM gene provides instructions for making the enzyme arginine:glycine amidinotransferase. This enzyme participates in the two-step production (synthesis) of the compound creatine from the protein building blocks (amino acids) glycine, arginine, and methionine. Specifically, arginine:glycine amidinotransferase controls the first step of the process. In this step, a compound called guanidinoacetic acid is produced by transferring a cluster of nitrogen and hydrogen atoms called a guanidino group from arginine to glycine. Guanidinoacetic acid is converted to creatine in the second step of the process. Creatine is needed for the body to store and use energy properly.
Related Information
At least two mutations in the GATM gene cause arginine:glycine amidinotransferase deficiency, a disorder that involves delayed development, intellectual disability, and in some cases muscle weakness. These mutations result in the production of an abnormally shortened arginine:glycine amidinotransferase enzyme or disrupt how genetic information is pieced together to make a blueprint for producing the enzyme.
GATM gene mutations interfere with the ability of the arginine:glycine amidinotransferase enzyme to participate in creatine synthesis, resulting in a shortage of creatine. The effects of arginine:glycine amidinotransferase deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.
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Cytogenetic Location: 15q21.1, which is the long (q) arm of chromosome 15 at position 21.1
Molecular Location: base pairs 45,361,124 to 45,402,227 on chromosome 15 (Homo sapiens Updated Annotation Release 109.20190905, GRCh38.p13) (NCBI)

Related Information
- AGAT
- AT
- GATM_HUMAN
- glycine amidinotransferase (L-arginine:glycine amidinotransferase)
- glycine amidinotransferase, mitochondrial
- glycine amidinotransferase, mitochondrial precursor
- L-arginine:glycine amidinotransferase
- transamidinase
Related Information
- Braissant O, Henry H, Béard E, Uldry J. Creatine deficiency syndromes and the importance of creatine synthesis in the brain. Amino Acids. 2011 May;40(5):1315-24. doi: 10.1007/s00726-011-0852-z. Epub 2011 Mar 10. Review.
- Béard E, Braissant O. Synthesis and transport of creatine in the CNS: importance for cerebral functions. J Neurochem. 2010 Oct;115(2):297-313. doi: 10.1111/j.1471-4159.2010.06935.x. Epub 2010 Aug 25. Review.
- Item CB, Stöckler-Ipsiroglu S, Stromberger C, Mühl A, Alessandrì MG, Bianchi MC, Tosetti M, Fornai F, Cioni G. Arginine:glycine amidinotransferase deficiency: the third inborn error of creatine metabolism in humans. Am J Hum Genet. 2001 Nov;69(5):1127-33. Epub 2001 Sep 10.
- OMIM: L-ARGININE:GLYCINE AMIDINOTRANSFERASE
- Morris SM Jr. Enzymes of arginine metabolism. J Nutr. 2004 Oct;134(10 Suppl):2743S-2747S; discussion 2765S-2767S. Review.
- Nasrallah F, Feki M, Kaabachi N. Creatine and creatine deficiency syndromes: biochemical and clinical aspects. Pediatr Neurol. 2010 Mar;42(3):163-71. doi: 10.1016/j.pediatrneurol.2009.07.015. Review.
- Schulze A. Creatine deficiency syndromes. Mol Cell Biochem. 2003 Feb;244(1-2):143-50. Review.
- Sykut-Cegielska J, Gradowska W, Mercimek-Mahmutoglu S, Stöckler-Ipsiroglu S. Biochemical and clinical characteristics of creatine deficiency syndromes. Acta Biochim Pol. 2004;51(4):875-82. Review.