Pediatric Endocrinology Diabetes and Metabolism

Guanidinoacetate methyltransferase deficiency: a rare but treatable cause of developmental and epileptic encephalopathy – a case report and literature review

Mikolaj Pielas 1
,
Julita Borkowska 1
,
Magdalena Kaczor 2

  1. Department of Neurology and Epileptology, The Children's Memorial Health Institute, Warsaw, Poland

  2. Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, Warsaw, Poland

Pediatr Endocrinol Diabetes Metab 2026; 32 (4):

DOI: https://doi.org/10.5114/pedm.2026.163393
Data publikacji online: 2026/08/07
Article file
0434_Guanidinoacetate (1).pdf
Confronting perimenopausal women’s knowledge of coronary heart disease with their health behaviours. Controversial role of hormone replacement therapy in the protection of coronary heart disease
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  2. Verhoeven NM, Guérand WS, Struys EA, et al. Plasma creatinine assessment in creatine deficiency: a diagnostic pitfall. J Inherit Metab Dis 2000; 23: 835–840. doi: 10.1023/A:1026764703486.
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  8. Khaikin Y, Sidky S, Abdenur J, et al. Treatment outcome of twenty-two patients with guanidinoacetate methyltransferase deficiency: an international retrospective cohort study. Eur J Paediatr Neurol 2018; 22: 369–379. doi: 10.1016/j.ejpn.2018.02.007.
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  12. Engelke UFH, Tassini M, Hayek J, et al. Guanidinoacetate methyltransferase (GAMT) deficiency diagnosed by proton NMR spectroscopy of body fluids. NMR Biomed 2009; 22: 538–544. doi: 10.1002/NBM.1367.
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  14. Bianchi MC, Tosetti M, Battini R, et al. Treatment monitoring of brain creatine deficiency syndromes: a 1H- and 31P-MR spectroscopy study. AJNR Am J Neuroradiol 2007; 28: 548–554.
  15. Stöckler S, Marescau B, De Deyn PP, et al. Guanidino compounds in guanidinoacetate methyltransferase deficiency, a new inborn error of creatine synthesis. Metabolism 1997; 46: 1189–1193. doi: 10.1016/S0026-0495(97)90215-8.
  16. Stockler-Ipsiroglu S, van Karnebeek C, Longo N, et al. Guanidinoacetate methyltransferase (GAMT) deficiency: outcomes in 48 individuals and recommendations for diagnosis, treatment and monitoring. Mol Genet Metab 2014; 111: 16–25. doi: 10.1016/ J.YMGME.2013.10.018.
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  22. Sinclair GB, van Karnebeek CDM, Ester M, et al. A three-tier algorithm for guanidinoacetate methyltransferase (GAMT) deficiency newborn screening. Mol Genet Metab 2016; 118: 173–177. doi: 10.1016/j.ymgme.2016.05.002.
  23. Pasquali M, Schwarz E, Jensen M, et al. Feasibility of newborn screening for guanidinoacetate methyltransferase (GAMT) deficiency. J Inherit Metab Dis 2014; 37: 231–236. doi: 10.1007/S10545-013-9662-7.
  24. Ream MA, Lam WKK, Grosse SD, et al. Evidence and recommendation for guanidinoacetate methyltransferase deficiency newborn screening. Pediatrics 2023; 152: e2023062100. doi: 10.1542/peds.2023-062100.
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