Van Hove J, Coughlin C II, Swanson M, Hennermann JB. Nonketotic hyperglycinemia. 2002 Nov 14 [Updated 2019 May 23]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2019. https://www.ncbi.nlm.nih.gov/books/NBK1357/.

Coughlin C II, Swanson MA, Kronquist K, Acquaviva C, Hutchin T, Rodriguez-Pombo P, et al. The genetic basis of classic nonketotic hyperglycinemia due to mutations in GLDC and AMT. Genet Med. 2017;19:104–11.

Article  PubMed  Google Scholar 

Perry TL, Urquhart N, Maclean J, Evans ME, Hanson S, Davidson AGF, et al. Nonketotic hyperglycinemia: glycine accumulation due to absence of glycine cleavage in the brain. N Engl J Med. 1975;292:1269–73.

Article  PubMed  Google Scholar 

Hennermann JB, Berger JM, Grieben U, Scharer G, Van Hove JLK. Prediction of long-term outcome in glycine encephalopathy: a clinical survey. J Inherit Metab Dis. 2012;35(2):253–61.

Article  PubMed  Google Scholar 

Swanson MA, Coughlin CR II, Scharer GH, Szerlong HJ, Bjoraker KJ, Spector EB, et al. Biochemical and molecular predictors of prognosis in nonketotic hyperglycinemia. Ann Neurol. 2015;78:606–18.

Article  PubMed  Google Scholar 

Dinopoulos A, Matsubara Y, Kure S. Atypical variants of nonketotic hyperglycinemia. Mol Genet Metab. 2005;86:61–9.

Article  PubMed  Google Scholar 

De Groot CJ, Troelstra JA, Hommes FA. Nonketotic hyperglycinemia: an in vitro study of the glycine-serine conversion in liver of three patients and the effect of dietary methionine. Pediatr Res. 1970;4:238–43.

Article  PubMed  Google Scholar 

Pai YJ, Leung KY, Savery D, Hutchin T, Prunty H, Heales S, et al. Glycine decarboxylase deficiency causes neural tube defects and features of non-ketotic hyperglycinemia in mice. Nature Commun. 2015;4(6):6388.

Article  Google Scholar 

Leung KY, Pai YJ, Chen Q, Santos C, Calvani E, Sudiwala S, et al. Partitioning of one-crbon units in folate and methionine metabolism is essential for neural tube closure. Cell Rep. 2017;21(7):1795–808.

Article  PubMed  Google Scholar 

De Groot CJ, Everts RS, Gramsbergen A, Hommes FA. A study of the pathogenesis of non-ketotic hyperglycinemia. In: Hommes FA, editor. Models for the study of inborn errors of metabolism, Elsevier; 1979.

De Groot CJ, Everts RE. The age-dependent toxicity of glycine. J Inherit Metab Dis. 1982;5(Suppl2):124–5.

Article  Google Scholar 

Leipnitz G, Solano AF, Seminotti B, Amaral AU, Fernandes CG, Beskow AP, et al. Glycine provides lipid oxidative damage and reduces the antioxidant defenses in brain cortex of young rats. Cell Mol Neurobiol. 2009;29(2):253–61.

Article  PubMed  Google Scholar 

Seminotti B, Knebel LA, Amaral AU, de Rosa MS, Eichler P, Leipnitz G, et al. Glycine intrastriatal administration induces lipid and protein oxidative damage and alters the enzymatic antioxidant defenses in rat brain. Life Sci. 2011;89(7–8):276–81.

Article  PubMed  Google Scholar 

Moura AP, Parmeggiani B, Grings M, Alvorcem LM, Boldrini RM, Bumbel AP, et al. Intracerebral glycine administration impairs energy and redox homeostasis and induces glial reactivity in cerebral cortex of newborn rats. Mol Neurobiol. 2016;53(9):5864–75.

Article  PubMed  Google Scholar 

McDonald JW, Johnston MV. Nonketotic hyperglycinemia: pathophysiological role of the NMDA-type excitatory amino acid receptors. Ann Neurol. 1990;27:449–50.

Article  PubMed  Google Scholar 

Tada K, Kure S. Non-ketotic hyperglycinaemia: molecular lesion, diagnosis and pathophysiology. J Inherit Metab Dis. 1993;16:691–703.

Article  PubMed  Google Scholar 

Deutsch SI, Rosse RB, Mastropaolo J. Current status of NMDA antagonist interventions in the treatment of nonketotic hyperglycinemia. Rev Clin Neuropharmacol. 1998;21:71–9.

Google Scholar 

Hamosh A, Mcdonald JW, Valle D, Francomano CA, Niedermeyer E, Johnson JV. Dextromethorphan and high-dose benzoate therapy for nonketotic hyperglycinemia in an infant. J Pediatr. 1992;121:131–5.

Article  PubMed  Google Scholar 

Hamosh A, Maher JF, Bellus GA, Rasmussen SA, Johnston MV. Long-term use of high-dose benzoate and dextromethorphan for the treatment of nonketotic hyperglycinemia. J Pediatr. 1998;132:709–13.

Article  PubMed  Google Scholar 

Van Hove JLK, Vande Kerckhove K, Hennermann JB, Mahieu V, Declercq P, Mertens S, et al. Benzoate treatment and the glycine index in nonketotic hyperglycinaemia. J Inherit Metab Dis. 2005;28:651–63.

Article  PubMed  Google Scholar 

Bjoraker KJ, Swanson MA, Coughlin CR II, Christodoulou J, Tan ES, Fergeson M, et al. Neurodevelopmental outcome and treatment efficacy of benzoate and dextromethorphan in siblings with attenuated nonketotic hyperglycinemia. J Pediatr. 2016;170:234–9.

Article  PubMed  Google Scholar 

Beyoğlu D, Idle DR. The glycine deportation system and its pharmacological consequences. Pharmacol Ther. 2012;135(2):151–67.

Article  PubMed  Google Scholar 

Leung K-Y, De Castro SCP, Santos C, Savery D, Prunty H, Gold-Diaz D, et al. Regulation of glycine metabolism by the glycine cleavage system and conjugation pathway in mouse models of non-ketotic hyperglycinemia. J Inherit Metab Dis. 2020;43(6):1186–98.

Article  PubMed  Google Scholar 

Boneh A, Degani Y, Harari M. Prognostic clues and outcome of early treatment of nonketotic hyperglycinemia. Pediatr Neurol. 1996;15:137–41.

Article  PubMed  Google Scholar 

Rogers AS, Shaughnessy KK, Davis LS. Dermatitis and dangerous diets: a case of kwashiorkor. JAMA Dermatol. 2014;150(8):910–1.

Article  PubMed  Google Scholar 

Samadi JA, Schwartz RA, Shih LY, Piela Z, Lambert WC, Janniger CK. Acrodermatitis enteropathica-like eruption in an infant with nonketotic hyperglycinemia. J Dermatol. 2000;27(9):604–8.

Article  Google Scholar 

Cusmai R, Martinelli D, Moavero R, et al. Ketogenic diet in early myoclonic encephalopathy due to non ketotic hyperglycinemia. Eur J Paediatr Neurol. 2012;16(5):509–13.

Article  PubMed  Google Scholar 

Kava MP, Robertson A, Greed L, Balasubramaniam S. Ketogenic diet, a potentially valuable therapeutic option for the management of refractory epilepsy in classical neonatal nonketotic hyperglycinemia: a case report. Eur J Clin Nutr. 2019;73(6):961–5.

Article  PubMed  Google Scholar 

Iqbal M, Prasad M, Mordekar SR. Nonketotic hyperglycinemia case series. J Pediatr Neurosci. 2015;10(4):355–8.

Article  PubMed  Google Scholar 

Daida A, Hamano S-I, Ikemoto S, et al. Use of perampanel and a ketogenic diet in nonketotic hyperglycinemia: a case report. Neuropediatrics. 2020;51(6):417–20.

Article  PubMed  Google Scholar 

Shbarou RM, Boustany RM, Daher RT, Pakdel P, Noureddine A, Karam PE. Outcome of nonketotic hyperglycinemia in Lebanon: 14-year retrospective review. Neuropediatrics. 2019;50(4):235–43.

Article  PubMed  Google Scholar 

Appavu B, Vanatta L, Condie J, Kerrigan JF, Jarrar R. Ketogenic diet treatment for pediatric super-refractory status epilepticus. Seizure. 2016;41:62–5.

Article  PubMed  Google Scholar 

Bzduch V, Behulova D, Kolnikova M, Payerova J. Fabriciova K Ketogenic diet in nonketotic hyperglycinemia. J Inherited Metab Dis. 2020;33(Suppl 1):S31.

Google Scholar 

Aikawa T, Marsutaka H, Takezawa K, Ishikawa E. Gluconeogenesis and amino acid metabolism, I: comparison of various precursors for hepatic gluconeogenesis in vivo. Biochim Biophys Acta. 1972;279(2):234–44.

Article  PubMed  Google Scholar 

Wolff JA, Kulovich S, Yu AL, Qiao CN, Nyhan WL. The effectiveness of benzoate in the management of seizures in nonketotic hyperglycinemia. Am J Dis Child. 1986;140:596–602.

PubMed  Google Scholar 

Van Hove JLK, Kishnani P, Muenzer J, Wenstrup RJ, Summar ML, Brummond MR, et al. Benzoate therapy and carnitine deficiency in non-ketotic hyperglycinemia. Am J Med Genet. 1995;59(4):444–53.

Article  PubMed  Google Scholar 

Korman SH, Boneh A, Ichnohe A, Kojima K, Sato K, Ergaz Z, et al. Persistent NKH with transient or absent symptoms and a homozygous GLDC mutation. Ann Neurol. 2004;56:139–43.

Article  PubMed  Google Scholar 

Heindel W, Kugel H, Roth B. Noninvasive detection of increased glycine content by proton MR spectroscopy in the brains of two infants with nonketotic hyperglycinemia. Am J Neuroradiol. 1993;14:629–35.

PubMed  Google Scholar 

Shin JH, Ahn SY, Shin JH, Sung SI, Jung JM, Kim JK, et al. Sequential magnetic resonance spectroscopic changes in a patient with nonketotic hyperglycinemia. Korean J Pediatr. 2012;55:301–5.

Article  PubMed  Google Scholar 

Stence NV, Fenton LZ, Levek C, Tong S, Coughlin CR II, Hennermann JB, et al. Brain imaging in classic nonketotic hyperglycinemia: quantitative analysis and relation to phenotype. J Inherit Metab Dis. 2019;42:438–50.

Article  PubMed  Google Scholar 

Provencher SW. Estimation of metabolite concentrations from localized in vivo proton NMR spectra. Magn Reson Med. 1993;30:672–9.

Article  PubMed  Google Scholar 

Provencher SW. Automatic quantitation of localized in vivo 1H spectra with LCModel. NMR Biomed. 2001;14:260–4.

Article  PubMed  Google Scholar 

Burton BK, Pettenati MJ, Block SM, Bensen J, Roach ES. Nonketotic hyperglycinemia in a patient with the 9p- syndrome. Am J Med Genet. 1989;32(4):504–5.

Article  PubMed  Google Scholar 

Tekgul H, Serdaroglu G, Karapinar B, Polat M, Yurtsever S, et al. Vigabatrin caused rapidly progressive deterioration in two cases with early myoclonic encephalopathy associated with nonketotic hyperglycinemia. J Child Neurol. 2006;21(1):82–4.

Article  PubMed  Google Scholar 

Swanson MA, Miller K, Young SP, Tong S, Ghaloul-