Guanidinoacetate methyltransferase deficiency typically presents with muscular hypotonia, global developmental delay, extrapyramidal signs, and seizures during infancy and childhood. The authors report a 5-year-old child with guanidinoacetate methyltransferase deficiency who presented with severe speech delay, emphasizing the importance of an early screening for disorders of creatine synthesis and transport in every infant or child with isolated speech delay of unknown cause.
Stockler S., Holzbach U., Hanefeld F., et al. Creatine deficiency in the brain: a new, treatable inborn error of metabolism. Pediatr Res.1994;36:409-413.
2.
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; 58:914-922.
3.
Sykut-Cegielska J., Gradowska W., Mercimek-Mahmutoglu S., Stockler-Ipsiroglu S.Biochemical and clinical characteristics of creatine deficiency syndromes. Acta Biochim Pol. 2004;51: 875-882.
4.
Schulze A., Hess T., Wevers R., et al. Creatine deficiency syndrome caused by guanidinoacetate methyltransferase deficiency: diagnostic tools for a new inborn error of metabolism. J Pediatr.1997; 131:626-631.
5.
Bodamer OA, Bloesch SM, Gregg AR, Stockler-Ipsiroglu S., O'Brien WEAnalysis of guanidinoacetate and creatine by isotope dilution electrospray tandem mass spectrometry. Clin Chim Acta.2001;308:173-178.
6.
Carducci C., Santagata S., Leuzzi V., et al. Quantitative determination of guanidinoacetate and creatine in dried blood spot by flow injection analysis-electrospray tandem mass spectrometry . Clin Chim Acta. 2006;364:180-187.
7.
Item CB, Stockler-Ipsiroglu S., Willheim C., Muhl A., Bodamer OAUse of denaturing HPLC to provide efficient detection of mutations causing guanidinoacetate methyltransferase deficiency. Mol Genet Metab.2005;86:328-334.