Research Notes: Creatine Supplementation for Creatine Synthesis and Transport Disorders
and Other Genetic Neurological Disorders
Note: This page contains abstracts regarding the use of creatine for creatine synthesis and transport disorders (which primarily affect the brain) and other disorders with prominent neurological features such as maple sugar urine disease (MSUD, branched chain amino aciduria) and methylmalonic acidemia. Please see here for abstracts and other materials primarily having to do with the use of creatine for the treatment of myopathy (muscle problems).
Neurochem Res. 2007 Aug 8.
Inhibition of Brain Energy Metabolism by the Branched-chain Amino Acids Accumulating in Maple Syrup Urine Disease.
Ribeiro CA, Sgaravatti AM, Rosa RB, Schuck PF, Grando V, Schmidt AL, Ferreira GC, Perry ML, Dutra-Filho CS, Wajner M.
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, CEP, Brazil.
In the present work we investigated the in vitro effect of the branched-chain amino acids (BCAA) accumulating in maple syrup urine disease (MSUD) on some parameters of energy metabolism in cerebral cortex of rats. (14)CO(2) production from [1-(14)C]acetate, [1-5-(14)C]citrate and [U-(14)C]glucose, as well as glucose uptake by the brain were evaluated by incubating cortical prisms from 30-day-old rats in the absence (controls) or presence of leucine (Leu), valine (Val) or isoleucine (Ile). All amino acids significantly reduced (14)CO(2) production by around 20-55%, in contrast to glucose utilization, which was significantly increased by up to 90%. Furthermore, Leu significantly inhibited the activity of the respiratory chain complex IV, whereas Val and Ile markedly inhibited complexes II-III, III and IV by up to 40%. We also observed that trolox (alpha-tocopherol) and creatine totally prevented the inhibitory effects provoked by the BCAA on the respiratory chain complex activities, suggesting that free radicals were involved in these effects. The results indicate that the major metabolites accumulating in MSUD disturb brain aerobic metabolism by compromising the citric acid cycle and the electron flow through the respiratory chain. We presume that these findings may be of relevance to the understanding of the pathophysiology of the neurological dysfunction of MSUD patients.
Epilepsia. 2007 Jun.
Severe Epilepsy in X-Linked Creatine Transporter Defect (CRTR-D).
Mancardi MM, Caruso U, Schiaffino MC, Baglietto MG, Rossi A, Battaglia FM, Salomons GS, Jakobs C, Zara F, Veneselli E, Gaggero R.
Department of Child Neuropsychiatry, Epilepsy Unit, G. Gaslini Institute, Genoa, Italy.
Disorders of creatine synthesis or its transporter resulting in neurological impairment with mental retardation and epilepsy have only been recognized in recent years. To date, the epileptic disorder observed in creatine transporter deficiency (CRTR-D) has been described as a mild phenotype with infrequent seizures and favorable response to common antiepileptic drugs. We report on a 5 year-old boy with known speech delay who presented with severe and refractory epilepsy. After extensive investigations, metabolite analysis and brain 1H-MRS suggested CRTR-D, which was confirmed by the detection of a known pathogenic mutation in the SLC6A8 gene (c.1631C>T; p.Pro544Leu).
Mol Genet Metab. 2007 Apr 25.
Successful treatment of a guanidinoacetate methyltransferase deficient patient: Findings with relevance to treatment strategy and pathophysiology.
Verbruggen KT, Sijens PE, Schulze A, Lunsing RJ, Jakobs C, Salomons GS, van Spronsen FJ.
Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, The Netherlands.
Biochemical and developmental results of treatment of a guanidinoacetate methyltransferase (GAMT) deficient patient with a mild clinical presentation and remarkable developmental improvement after treatment are presented. Treatment with creatine (Cr) supplementation resulted in partial normalization of cerebral (measured with magnetic resonance proton spectroscopy) and plasma levels of Cr and guanidinoacetate (GAA). Addition of high dose ornithine to the treatment led to further normalization of plasma GAA, while cerebral Cr and GAA did not improve further.
Annu Rev Nutr. 2007 Apr 12.
Creatine: Endogenous Metabolite, Dietary, and Therapeutic Supplement.
Brosnan JT, Brosnan ME.
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
Creatine and phosphocreatine serve not only as an intracellular buffer for adenosine triphosphate, but also as an energy shuttle for the movement of high-energy phosphates from mitochondrial sites of production to cytoplasmic sites of utilization. The spontaneous loss of creatine and of phosphocreatine to creatinine requires that creatine be continuously replaced; this occurs by a combination of diet and endogenous synthesis. Vegetarians obtain almost no dietary creatine. Creatine synthesis makes major demands on the metabolism of glycine, arginine, and methionine. Large doses of creatine monohydrate are widely taken, particularly by athletes, as an ergogenic supplement; creatine supplements are also taken by patients suffering from gyrate atrophy, muscular dystrophy, and neurodegenerative diseases. Children with inborn errors of creatine synthesis or transport present with severe neurological symptoms and a profound depletion of brain creatine. It is evident that creatine plays a critical, though underappreciated, role in brain function.
Rev Neurol. 2007 Mar 16-31.
Cerebral creatine transporter deficiency: an infradiagnosed neurometabolic disease. [Article in Spanish]
Campistol J, Arias-Dimas A, Poo P, Pineda M, Hoffman M, Vilaseca MA, Artuch R, Ribes A.
Hospital Sant Joan de Deu, 08950 Esplugues de Llobregat, Espana.
Introduction. Brain creatine deficiencies are a group of inborn errors of metabolism recently recognized which are caused by arginine: glycine amidinotransferase (AGAT) deficiency, guanidinoacetate metiltransferase (GAMT) deficiency and defects in creatine transporter (CRTR). Although all of them are characterized by a brain creatine deficiency, clinical and biochemical features are different. Case reports. We present a retrospective study about four patients of masculine sex affected of creatine transporter defects who were recently diagnosed in our centre. We describe the clinical presentation features, the different tests that we used in the diagnosis process (brain magnetic resonance spectroscopy, biochemical analysis of guanidinoacetate and creatine/creatinine ratio in urine), evolution aspects and the response to treatment. The most significative clinical feature was developmental delay mainly in expressive speech, they also presented epilepsy (three cases), autism (three cases), hypotonia (one case) and microcephalia (one case). Brain magnetic resonance spectroscopy showed a low (three cases) or an absence (one case) of creatine level. To confirm the defect we studied the creatine uptake in fibroblasts and molecular analysis of the SLC6A8/creatine transporter gene. Patients with creatine transporter deficiency are being treated with arginine, because a lack of response to creatine. Conclusion. Cerebral creatine transporter deficiency can present with different neurological symptoms but developmental and language delay and epilepsy are the most significative; diagnosis is easy and there are some therapeutical options.
AJNR Am J Neuroradiol. 2007 Mar.
Treatment Monitoring of Brain Creatine Deficiency Syndromes: A 1H- and 31P-MR Spectroscopy Study.
Bianchi MC, Tosetti M, Battini R, Leuzzi V, Alessandri' MG, Carducci C, Antonozzi I, Cioni G.
Department of Neuroradiology, Santa Chiara Hospital, Pisa, Italy.
Background and purpose: Brain creatine (Cr) deficiencies (BCr-d) are rare disorders of creatine biosynthesis and transport. We performed consecutive measures of total Cr (tCr) and of its phosphorylated fraction, phosphocreatine (PCr), in the brains of children affected by Cr synthesis defects during a long period of therapy. The aim was to identify the optimal treatment strategy for these disorders. Materials and methods: Two patients with guanidinoacetate methyltransferase defect (GAMT-d) were treated with different amounts of Cr and with diet restrictions aimed at reducing endogenous guanidinoacetate (GAA) synthesis. Three patients with arginine:glycine amidinotransferase defect (AGAT-d) were treated with different Cr intakes. The patients' treatments were monitored by means of (1)H- and (31)P-MR spectroscopy. Results: Cr and PCr replenishment was lower in GAMT-d than in AGAT-d even when GAMT-d therapy was carried out with a very high Cr intake. Cr and especially PCr replenishment became more efficient only when GAA blood values were reduced. Adenosine triphosphate (ATP) was increased in the baseline phosphorous spectrum of GAMT-d, and it returned to a normal value with treatment. Brain pH and brain P(i) showed no significant change in the AGAT-d syndrome and at any Cr intake. However, 1 of the 2 GAMT-d patients manifested a lower brain pH level while consuming the GAA-lowering diet. Conclusions: AGAT-d treatment needs lower Cr intake than GAMT-d. Cr supplementation in GAMT-d treatment should include diet restrictions aimed at reducing GAA concentration in body fluids. (1)H- and especially (31)P-MR spectroscopy are the ideal tools for monitoring the therapy response to these disorders.
Neurochem Res. 2007 Feb 2.
Guanidinoacetate Inhibits Glutamate Uptake in Rat Striatum of Rats at Different Ages.
Zugno AI, Oliveira DL, Scherer EB, Wajner M, Wofchuk S, Wyse AT.
Departamento de Bioquimica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
Glutamate plays a central role in the excitatory synaptic transmission and is important for brain development and functioning. Increased glutamate levels in the synaptic cleft are related to neuronal damage associated with excitotoxicity. Guanidinoacetate methyltransferase (GAMT) deficiency is an inherited neurometabolic disorder biochemically characterized by tissue accumulation of guanidinoacetate (GAA) and depletion of creatine. Affected patients present epilepsy and mental retardation whose pathogeny is unclear. In the present study we investigated the in vitro and in vivo (intrastriatal administration) effect of GAA on glutamate uptake by striatum slices of developing and adult rats. Results showed that GAA significantly inhibited in vitro glutamate uptake at 50 muM and 100 muM in all ages tested. We also tested the effect of taurine on the inhibition of glutamate uptake caused by GAA. Taurine significantly attenuated the inhibitory effect caused by 50 muM GAA, but did not alter that provoked by 100 muM GAA. Furthermore, intrastriatal administration of a solution of 30 muM GAA (0.06 nmol/striatum) significantly inhibited glutamate uptake by rat striatum slices. Our results suggest that the inhibition of striatal glutamate uptake caused by GAA might be involved in the neuropathology and especially in the acute neurological features present in patients with GAMT-deficiency.
J Inherit Metab Dis. 2007 Feb.
Guanidinoacetate methyltransferase deficiency masquerading as a mitochondrial encephalopathy.
Morris AA, Appleton RE, Power B, Isherwood DM, Abernethy LJ, Taylor RW, Turnbull DM, Verhoeven NM, Salomons GS, Jakobs C.
Willink Unit, Royal Manchester Children's Hospital, Manchester, UK.
Guanidinoacetate methyltransferase (GAMT) deficiency is a rare disorder of creatine synthesis. We report a patient who presented at 10 months of age with hypotonia and global developmental delay. Subsequently, she developed seizures and choreoathetosis. Magnetic resonance imaging showed high signal bilaterally in the globus pallidus on T2-weighted images. Mitochondrial respiratory chain studies revealed low complex I activity (in muscle 0.052 nmol NADH oxidized per min per unit citrate synthase, controls 0.166 +/- 0.047; in fibroblasts 0.080 nmol NADH oxidized per min per unit citrate synthase, controls 0.197 +/- 0.034). The true diagnosis was suspected at 21 months of age because of persistent low plasma and urine creatinine concentrations. GAMT activity was undetectable in fibroblasts and compound heterozygous mutations were found in the GAMT gene (c.327G>A and c.522G>A). The patient was treated with creatine, dietary arginine restriction and ornithine supplements. Her movement disorder and seizures resolved but she still has severe cognitive impairment and no expressive language. The occurrence of secondary respiratory chain abnormalities in GAMT deficiency may lead to misdiagnosis, particularly as the clinical and radiological features resemble those seen in mitochondrial encephalopathies. It is important to establish the correct diagnosis because specific treatment is available.
Am J Physiol Regul Integr Comp Physiol. 2006 Dec 21.
Cerebral energetic effects of creatine supplementation in humans.
Pan JW, Takahashi K.
Neurosurgery, Yale University School of Medicine, New haven, Connecticut, United States.
There has been considerable interest in the use of creatine supplementation to treat neurological disorders. However in contrast to muscle physiology, there are relatively few studies of creatine supplementation in the brain. In this report we use high field MR (31)P and 1H spectroscopic imaging of human brain with a 7 day protocol of oral creatine supplementation to examine its effects on cerebral energetics (phosphocreatine PCr, ATP) and mitochondrial metabolism (N-acetyl aspartate NAA, and creatine Cr). We find an increased ratio of PCr/ATP (Day0 0.80+/-0.10; Day7 0.85+/-0.09) with this change largely due to decreased ATP, from 2.7+/-0.3mM to 2.5+/-0.3mM. The ratio of NAA/Cr also decreased (Day0 1.32+/-0.17; Day7 1.18+/-0.13), primarily from increased Cr (9.6+/-1.9 to 10.1+/-2.0mM). The creatine-induced changes significantly correlated with the basal state, with the fractional increase in PCr/ATP negatively correlating with the basal PCr/ATP value (R=-0.74, p<0.001). As NAA is a measure of mitochondrial function, there was also a significant negative correlation between basal NAA concentrations with the fractional change in PCr and ATP. Thus, healthy human brain energetics is malleable, and shifts with 7 days of creatine supplementation, with the regions of initially low PCr showing the largest increments in PCr. Overall, creatine supplementation appears to improve high energy phosphate turnover and in healthy brain, and can result in either a decrease or increase in high energy phosphate concentrations.
Eur J Pediatr. 2006 Dec 21.
Global developmental delay in guanidionacetate methyltransferase deficiency: differences in formal testing and clinical observation.
Verbruggen KT, Knijff WA, Soorani-Lunsing RJ, Sijens PE, Verhoeven NM, Salomons GS, Goorhuis-Brouwer SM, van Spronsen FJ.
University Medical Center Groningen, Beatrix Children's Hospital, University of Groningen, P.O. Box 30001, 9700 RB, Groningen, The Netherlands.
Guanidinoacetate N-methyltransferase (GAMT) deficiency is a defect in the biosynthesis of creatine (Cr). So far, reports have not focused on the description of developmental abilities in this disorder. Here, we present the result of formal testing of developmental abilities in a GAMT-deficient patient. Our patient, a 3-year-old boy with GAMT deficiency, presented clinically with a severe language production delay and nearly normal nonverbal development. Treatment with oral Cr supplementation led to partial restoration of the cerebral Cr concentration and a clinically remarkable acceleration of language production development. In contrast to clinical observation, formal testing showed a rather harmonic developmental delay before therapy and a general improvement, but no specific acceleration of language development after therapy. From our case, we conclude that in GAMT deficiency language delay is not always more prominent than delays in other developmental areas. The discrepancy between the clinical impression and formal testing underscores the importance of applying standardized tests in children with developmental delays. Screening for Cr deficiency by metabolite analysis of body fluids or proton magnetic resonance spectroscopy of the brain deficiency should be considered in any child with global developmental delay/mental retardation lacking clues for an alternative etiology.
Mol Genet Metab. 2006 Nov.
High cerebral guanidinoacetate and variable creatine concentrations in argininosuccinate synthetase and lyase deficiency: implications for treatment?
van Spronsen FJ, Reijngoud DJ, Verhoeven NM, Soorani-Lunsing RJ, Jakobs C, Sijens PE.
Department of Metabolic Diseases, Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
Cerebral creatine and guanidinoacetate and blood and urine metabolites were studied in four patients with argininosuccinate synthetase (ASS) or argininosuccinate lyase (ASL) deficiency receiving large doses of arginine. Urine and blood metabolites varied largely. Cerebral guanidinoacetate was increased in all patients, while cerebral creatine was low in ASS and high in ASL deficiency. Because high cerebral guanidinoacetate might be toxic, lowering the arginine supplementation with additional creatine supplementation might be important.
Rev Neurol. 2006 Sep 1-15.
Diagnosis and treatment of brain creatine deficiency syndromes. [Article in Spanish]
Arias-Dimas A, Vilaseca MA, Artuch R, Ribes A, Campistol J.
Servico de Bioquimica. Hospital Sant Joan de Deu, 08950 Esplugues de Llobregat, Espana.
Aim: To review the clinical, biochemical and genetic aspects of brain creatine deficiency syndromes, as well as the therapeutic options available. Development: Brain creatine deficiency syndrome has recently been described as a series of inborn errors of metabolism that affect the synthesis and transport of creatine. Three metabolic defects are known: two affect synthesis - guanidinoacetate methyltransferase (GAMT) and arginine:glycine amidinotransferase (AGAT)- and one affects the transport of creatine. Clinically, these patients can display mental retardation, language disorders, epilepsy, autistic behaviour, neurological impairment and movement disorders. After the clinical selection, the different defects can be identified by a biochemical study involving the analysis of metabolites in biological fluids (guanidinoacetate and creatine/ creatinine ratio). Before continuing with the molecular studies, it is important to confirm the deficiency of brain creatine by means of magnetic resonance imaging with spectroscopy. Diagnostic confirmation of AGAT and GAMT deficits is carried out by determining the enzymatic activity in fibroblasts or lymphoblasts, or the incorporation of creatine in the case of studies of transport defects. The study of mutations in AGAT, GAMT (autosomal recessive inheritance) and SLC6A8 (X-linked) genes completes the diagnosis. Conclusions: Brain creatine deficiency syndromes are mainly associated to mental retardation and autism. GAMT and AGAT deficiencies respond to treatment with creatine, whereas patients with transport defects do not respond to this therapy; new therapeutic approaches are therefore being evaluated for this disease.
Neurology. 2006 Aug 22.
Presymptomatic treatment of neonatal guanidinoacetate methyltransferase deficiency.
Schulze A, Hoffmann GF, Bachert P, Kirsch S, Salomons GS, Verhoeven NM, Mayatepek E.
Department of Pediatrics I, University Children's Hospital, Heidelberg, Germany.
Prospective observation in a neonate with guanidinoacetate methyltransferase deficiency (GAMT-D), a severe neurometabolic disorder, revealed increased guanidinoacetate levels at birth. After 14-month treatment with creatine, high-dose ornithine, benzoate, and an arginine-restricted diet, the patient's development is normal and she does not present any symptoms of GAMT-D. The authors' observation indicates that early detection of GAMT-D is possible in the neonatal period, and presymptomatic treatment may prevent its manifestation.
Neurology. 2006 Aug 8.
GAMT deficiency: features, treatment, and outcome in an inborn error of creatine synthesis.
Mercimek-Mahmutoglu S, Stoeckler-Ipsiroglu S, Adami A, Appleton R, Araujo HC, Duran M, Ensenauer R, Fernandez-Alvarez E, Garcia P, Grolik C, Item CB, Leuzzi V, Marquardt I, Muhl A, Saelke-Kellermann RA, Salomons GS, Schulze A, Surtees R, van der Knaap MS, Vasconcelos R, Verhoeven NM, Vilarinho L, Wilichowski E, Jakobs C.
Division of Biochemical Diseases, British Columbia Children's Hospital, Vancouver, Canada.
Background: Guanidinoactetate methyltransferase (GAMT) deficiency is an autosomal recessive disorder of creatine synthesis. The authors analyzed clinical, biochemical, and molecular findings in 27 patients. Methods: The authors collected data from questionnaires and literature reports. A score including degree of intellectual disability, epileptic seizures, and movement disorder was developed and used to classify clinical phenotype as severe, moderate, or mild. Score and biochemical data were assessed before and during treatment with oral creatine substitution alone or with additional dietary arginine restriction and ornithine supplementation. Results: Intellectual disability, epileptic seizures, guanidinoacetate accumulation in body fluids, and deficiency of brain creatine were common in all 27 patients. Twelve patients had severe, 12 patients had moderate, and three patients had mild clinical phenotype. Twenty-one of 27 (78%) patients had severe intellectual disability (estimated IQ 20 to 34). There was no obvious correlation between severity of the clinical phenotype, guanidinoacetate accumulation in body fluids, and GAMT mutations. Treatment resulted in almost normalized cerebral creatine levels, reduced guanidinoacetate accumulation, and in improvement of epilepsy and movement disorder, whereas the degree of intellectual disability remained unchanged. Conclusion: Guanidinoactetate methyltransferase deficiency should be considered in patients with unexplained intellectual disability, and urinary guanidinoacetate should be determined as an initial diagnostic approach.
J Pediatr. 2006 Jun.
Arginine:glycine amidinotransferase (AGAT) deficiency in a newborn: early treatment can prevent phenotypic expression of the disease.
Battini R, Alessandri MG, Leuzzi V, Moro F, Tosetti M, Bianchi MC, Cioni G.
Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy.
Arginine:glycine amidinotransferase deficiency is a treatable inborn error of creatine synthesis, characterized by mental retardation, language impairment, and behavioral disorders. We describe a patient in whom arginine:glycine amidinotransferase was diagnosed at birth and treated at 4 months with creatine supplementation. In contrast with his 2 older sisters, he had normal psychomotor development at 18 months.
J Neurol Sci. 2006 May 15.
Creatine prevents behavioral alterations caused by methylmalonic acid administration into the hippocampus of rats in the open field task.
Vasques V, Brinco F, Viegas CM, Wajner M.
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Although a variable degree of psychomotor delay/mental retardation is found in a considerable number of patients affected by methylmalonic acidemia, the mechanisms underlying the neuropathology of this disorder are still poorly defined. The present study investigated the effect of acute intrahippocampal administration of methylmalonic acid (MMA), the biochemical hallmark of this disease, on rat behavior in the open field task. Cannulated 60-day-old male Wistar rats received bilateral intrahippocampal injection of MMA (0.1-1.0 micromol) 10 min before training. Controls received 0.1-1.0 micromol NaCl. Testing session was performed 24 h later. We observed that rats administered with 1.0 micromol MMA, but not with lower doses, did not habituate in the open field task, reflecting a deficit of performance. Motor activity, assessed by the number of crossing responses, was the same at training for the groups infused with MMA or NaCl. The effect of MK-801 (15 nmol) and succinate (1.5 micromol) administered 30 min before MMA injection, and of creatine (50 mg/kg, i.p.) administered twice a day for 3 days on the behavioral alterations provoked by MMA in the open field task revealed that only the energetic substrate creatine prevented these effects, reflecting a possible compromise of brain energy production by MMA. The results indicate that high intrahippocampal concentrations of the major metabolite accumulating in methylmalonic acidemia compromises brain functioning, causing deficit of performance in the open field task that may be related to the psychomotor delay/mental retardation observed in the affected patients.
Cell Mol Neurobiol. 2006 Feb.
Creatine and antioxidant treatment prevent the inhibition of creatine kinase activity and the morphological alterations of C6 glioma cells induced by the branched-chain alpha-keto acids accumulating in maple syrup urine disease.
Funchal C, Schuck PF, Santos AQ, Jacques-Silva MC, Gottfried C, Pessoa-Pureur R, Wajner M.
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600 anexo, Porto Alegre, RS, Brazil.
Accumulation of the branched-chain alpha-keto acids (BCKA), alpha-ketoisocaproic acid (KIC), alpha-keto-beta-methylvaleric acid (KMV), and alpha-ketoisovaleric acid (KIV) and their respective branched-chain alpha-amino acids (BCAA) in tissues and biological fluids is the biochemical hallmark of patients affected by the neurometabolic disorder known as maple syrup urine disease (MSUD). Considering that brain energy metabolism is possibly altered in MSUD, the objective of this study was to determine creatine kinase (CK) activity, a key enzyme of energy homeostasis, in C6 glioma cells exposed to BCKA. The cells were incubated with 1, 5, or 10 mM BCKA for 3 h and the CK activity measured afterwards. The results indicated that the BCKA significantly inhibited CK activity at all tested concentrations. Furthermore, the inhibition caused by the BCKA on CK activity was totally prevented by preincubation with the energetic substrate creatine and by coincubation with the N-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, indicating that deficit of energy and nitric oxide (NO) are involved in these effects. In contrast, other antioxidants such as glutathione (GSH) and trolox (soluble Vitamin E) were not able to prevent CK inhibition. In addition, we observed that the C6 cells changed their usual rounded morphology when exposed for 3 h to 10 mM BCKA and that creatine and L-NAME prevented these morphological alterations. Considering the importance of CK for brain metabolism homeostasis, it is conceivable that inhibition of this enzyme by increased levels of BCKA may contribute to the neurodegeneration of MSUD patients.
J Inherit Metab Dis. 2006 Feb.
X-Linked creatine transporter deficiency in two patients with severe mental retardation and autism.
Poo-Arguelles P, Arias A, Vilaseca MA, Ribes A, Artuch R, Sans-Fito A, Moreno A, Jakobs C, Salomons G.
Department of Neuropediatrics, Hospital Sant Joan de Deu, Barcelona, Spain.
We describe the first two unrelated Spanish patients with creatine transporter deficiency initially identified by brain proton magnetic resonance spectroscopy (MRS). The clinical phenotype was characterized by severe mental retardation, epilepsy, autism, severe speech delay and absence of brain creatine by MRS. Urine creatine/creatinine ratio was increased and creatine uptake in fibroblasts was impaired in both patients. On DNA sequence analysis of the SLC6A8/creatine transporter gene, one hemizygous mutation was found in each patient: one mutation was novel and consisted of a deletion of two nucleotides c.878-879delTC in exon 5, resulting in a frameshift (p.Lys293fsX3), and in the other patient a known deletion of three nucleotides 1222-1224delTTC in exon 8 resulting in p.Phe408del. Creatine treatment for one year failed to improve the neurological symptoms and was associated with a striking increase in body weight in both patients (13 and 16 kg, respectively).
Clin Chim Acta. 2006 Feb.
Quantitative determination of guanidinoacetate and creatine in dried blood spot by flow injection analysis-electrospray tandem mass spectrometry.
Carducci C, Santagata S, Leuzzi V, Carducci C, Artiola C, Giovanniello T, Battini R, Antonozzi I.
Dipartimento di Medicina Sperimentale e Patologia, Universita di Roma La Sapienza, Viale del Policlinico 155, 00161 Roma, Italy.
Background: Guanidinoacetate (GAA) and creatine (Cr) are reliable biochemical markers of primary creatine disorders. The aim of this study was to develop and validate a method for the determination of GAA and Cr in dried blood spot through the use of stable isotope dilution and flow injection analysis (FIA)-ESI-MS/MS. Methods: Dried blood spots were extracted using methanol-water solution containing D3-Cr. After evaporation and formation of butyl esters, samples were analyzed using multiple reaction monitoring mode (m/z 174.2-->101.1 for GAA, 188.3-->90.1 for Cr and 191.3-->93.1 for D3-Cr). Results: The analysis was very fast (1 min). The detection limits were 0.34 micromol/l of blood and 0.30 micromol/l of blood for Cr and GAA, respectively, and the response was linear over the range 0.25-12.5 micromol/l of blood for GAA and 3.57-624.7 micromol/l of blood for Cr. Recovery range was 93-101% for Cr and 94-105% for GAA and between-run CVs were 5.3% for GAA and 4.5% for Cr. Ion suppression effect was also studied. The method was applied to spots obtained from two patients affected by GAMT deficiency, four patients affected by AGAT deficiency (including a newborn) as well as 282 healthy subjects. Conclusions: The detection of GAA in dried blood spot by FIA-ESI-MS/MS is a highly reliable and high throughput method for the diagnosis of GAMT and AGAT deficiencies and a possible tool for newborn screening of both these tractable disorders.
Clin Chim Acta. 2005 Nov.
Laboratory diagnosis of defects of creatine biosynthesis and transport.
Verhoeven NM, Salomons GS, Jakobs C.
Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, de Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
In recent years, three inherited defects in the biosynthesis and transport of creatine have been described. The biosynthetic defects include deficiencies of L-arginine:glycine amidinotransferase and guanidinoacetate methyltransferase. The third defect is a functional defect in the creatine transporter (SLC6A8). Clinical symptoms of the three defects vary in severity, are aspecific and include mental retardation with severe speech delay, autistiform behaviour, and epilepsy. Some patients with GAMT deficiency exhibit a more complex clinical phenotype with extrapyramidal movement disorder. All three defects can be diagnosed by in vivo proton magnetic resonance spectroscopy of the brain, which shows a severe reduction or absence of creatine. Laboratory investigations for the diagnosis start with the analysis of guanidinoacetate, creatine and creatinine in body fluids (plasma and urine). Based on these findings, enzyme assays for AGAT or GAMT, or a creatine uptake assay for the transporter defect can be performed. DNA mutation analysis of the genes involved can prove the defects at the molecular level. To diagnose female patients with SLC6A8 deficiency, mutation analysis may be the only choice.
J Dev Behav Pediatr. 2005 Aug.
Incidence of brain creatine transporter deficiency in males with developmental delay referred for brain magnetic resonance imaging.
Newmeyer A, Cecil KM, Schapiro M, Clark JF, Degrauw TJ.
Division of Developmental Disabilities, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Several case reports describe children with global developmental delay who have brain creatine deficiency, where the deficiency was due to a lack of creatine transport into the brain or altered creatine synthesis. The purpose of this study was to determine what percentage of males with developmental delay referred for brain magnetic resonance imaging (MRI) at the authors' institution in a 12-month period was found to have brain creatine deficiency due to a defect in the creatine transporter gene. In the authors' facility, single voxel proton magnetic resonance spectroscopy (MRS) is routinely performed on any male child age 2 to 18 years with a history of language and/or developmental delay referred for a brain MRI. Charts for the 12-month time period were retrospectively reviewed. Fourteen subjects met inclusion criteria for global developmental delay. Two of the 14 patients had brain creatine deficiency on MRS. In the remaining 12, other structural and white matter abnormalities were identified. This study suggests that brain creatine deficiency is an important consideration in the differential diagnosis of males with global developmental delay referred for brain MRI; brain MRS should be considered in such cases.
Am J Med Genet A. 2005 Mar 1.
Guanidinoacetate methyltransferase deficiency identified in adults and a child with mental retardation.
Caldeira Araujo H, Smit W, Verhoeven NM, Salomons GS, Silva S, Vasconcelos R, Tomas H, Tavares de Almeida I, Jakobs C, Duran M.
Departamento de Quimica, Universidade da Madeira, Funchal, Portugal.
Our study describes the adult clinical and biochemical spectrum of guanidinoacetate methyltransferase (GAMT) deficiency, a recently discovered inborn error of metabolism. The majority of the previous reports dealt with pediatric patients, in contrast to the present study. A total of 180 institutionalized patients with a severe mental handicap were investigated for urine and plasma uric acid and creatinine. Patients with an increased urinary uric acid/creatinine ratio and/or decreased creatinine were subjected to the analysis of guanidinoacetate (GAA). Four patients (three related and one from an unrelated family) were identified with GAMT-deficiency. A fifth patient had died before a biochemical diagnosis could be made. They all had shown a normal psychomotor development for the first year of life, after which they developed a profound mental retardation. Three out of four had convulsions and all four totally lacked the development of speech. Their GAMT activity in lymphoblasts was impaired and two novel mutations were identified: the 59 G > C and 506 G > A missense mutations. Urinary GAA was increased, but highly variable 347-1,624 mmol/mol creat (Controls <150 mmol/mol creat). In plasma and CSF the GAA levels were fairly constant at 17.3-27.0 mumol/L (Controls 1.33-3.33) and 11.0-12.4 mumol/L, respectively (Controls 0.068-0.114). GAMT deficiency in adults is associated with severe mental retardation and absence or limited speech development. Convulsions may be prominent. The nonspecific nature of the clinical findings as well as the limited availability of GAA assays and/or in vivo magnetic resonance spectroscopy of the brain may mean that many more patients remain undiagnosed in institutions for persons with mental handicaps.
Rev Neurol (Paris). 2005 Mar.
Creatine deficiency syndromes. [Article in French]
Cheillan D, Cognat S, Vandenberghe N, Des Portes V, Vianey-Saban C.
Service de Biochimie Pediatrique, Hopital Debrousse, 29, rue Soeur-Bouvier, Lyon, France.
Introduction: Creatine deficiency syndromes are a newly described group of inborn errors of metabolism affecting creatine metabolism. Three diseases have been described: deficiency of arginine: glycine amidinotransferase (AGAT), deficiency of guanidinoacetate methyltransferase (GAMT) and creatine transporter defect (CRTR). State of art: These syndromes are characterized by a depletion of creatine/phosphocreatine in the brain. Clinically, most of the patients develop a variable mental retardation and a severe speech delay associated with epilepsy, extra-pyramidal syndrome and behavior disturbances. These diseases are often diagnosed during infancy but a few adult cases have been reported recently. Diagnosis is established by measurement of guanidinoacetate and creatine in biologic fluids and in vivo proton magnetic resonance spectroscopy by the total lack of intra-cerebral creatine/phosphocreatine demonstrating. GAMT and AGAT deficiencies are treatable by oral creatine supplementation whereas patients with CRTR do not respond to the treatment. Conclusion: Better knowledge of these syndromes is necessary to optimize diagnosis and patient management of these rare but potentially treatable disorders.
Am J Med Genet A. 2005 Jan 30.
Two novel mutations in SLC6A8 cause creatine transporter defect and distinctive X-linked mental retardation in two unrelated Dutch families.
Mancini GM, Catsman-Berrevoets CE, de Coo IF, Aarsen FK, Kamphoven JH, Huijmans JG, Duran M, van der Knaap MS, Jakobs C, Salomons GS.
Department of Clinical Genetics, Erasmus University MC/Sophia Children's Hospital, Rotterdam, The Netherlands.
Four Dutch male patients, two brothers from unrelated families were referred for investigation of psychomotor and severe language/speech delay. All four patients showed growth deficiency over the years. Facial features and poor body habitus were quite similar in the patients and in their mothers. Brain MRI showed nonspecific periventricular white matter lesions. In all the patients neuropsychological tests revealed moderate mental retardation, attention deficit and hyperactivity with impulsivity, a semantic-pragmatic language disorder, and oral dyspraxia. This specific cognitive profile is different from other children with mental retardation syndromes and seems to be unique. Excretion of creatine to creatinine ratio in urine of the four boys was increased compared to controls and their creatine uptake in fibroblasts was deficient. In the two brothers from the first pedigree, DNA sequence analysis revealed a novel mutation in the splice donor site in intron 10 (IVS10 + 5G>C, c.1495 + 5G>C) of the SLC6A8 gene leading to skipping of exon 10. In the other sib pair a novel missense mutation (c. 1361C>T; p.Pro544Leu) was found. These are the first families reported, in which the clinical suspicion of a creatine transporter disorder was raised on clinical grounds, before a brain 1H-MRS suggested the diagnosis. Screening of apparently X-linked mental retarded patients with this somatic and behavioral phenotype by the biochemical assay of creatine to creatinine ratio in the urine or DNA sequence analysis of SLC6A8 is worthwhile even when 1H-MRS is not available.
Mol Genet Metab. 2004 Jul.
Creatine and guanidinoacetate: diagnostic markers for inborn errors in creatine biosynthesis and transport.
Almeida LS, Verhoeven NM, Roos B, Valongo C, Cardoso ML, Vilarinho L, Salomons GS, Jakobs C.
Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands.
In this study, measurements of guanidinoacetate (GAA) and creatine (Cr) in urine, plasma, and cerebrospinal fluid (CSF) were performed using stable isotope dilution gas chromatography-mass spectrometry. Both compounds were analyzed in a single analysis. Reference values were established for GAA and Cr. These values were age dependent. No differences with gender were observed. Eight guanidinoacetate methyltransferase (GAMT) deficient patients and eight creatine transporter SLC6A8 deficient patients were investigated. In urine, plasma, and CSF of GAMT deficient patients increased levels of GAA are present. The SLC6A8 deficient patients all show increased creatine/creatinine (Cr/Crn) ratio in urine demonstrating the importance of the Cr/Crn ratio as a pathognomonic marker of the SLC6A8 deficiency.
Mol Genet Metab. 2004 Jul.
Guanidinoacetate methyltransferase deficiency: differences of creatine uptake in human brain and muscle.
Ensenauer R, Thiel T, Schwab KO, Tacke U, Stockler-Ipsiroglu S, Schulze A, Hennig J, Lehnert W.
Metabolic Unit, University Children's Hospital, Freiburg, Germany.
Deficiency of guanidinoacetate methyltransferase (GAMT), the first described creatine biosynthesis defect, leads to depletion of creatine and phosphocreatine, and accumulation of guanidinoacetate in brain. This results in epilepsy, mental retardation, and extrapyramidal movement disorders. Investigation of skeletal muscle by proton and phosphorus magnetic resonance spectroscopy before therapy demonstrated the presence of considerable amounts of creatine and phosphocreatine, and accumulation of phosphorylated guanidinoacetate in a 7-year-old boy diagnosed with GAMT deficiency, suggesting separate mechanisms for creatine uptake and synthesis in brain and skeletal muscle. The combination of creatine supplementation and a guanidinoacetate-lowering therapeutic approach resulted in improvement of clinical symptoms and metabolite concentrations in brain, muscle, and body fluids.
Mol Cell Biochem. 2004 Jul.
Presence of normal creatine in the muscle of a patient with a mutation in the creatine transporter: a case study.
Pyne-Geithman GJ, deGrauw TJ, Cecil KM, Chuck G, Lyons MA, Ishida Y, Clark JF.
Department of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
To date, more than seven families have been reported who carry a mutation in the X-linked creatine-transporter (CrT) gene. The resulting lack of creatine in the brain is associated with mental retardation, severe expressive language disorder, mild epilepsy, and a complete absence of Cr in the brain (measured using MRS). Conversely, these patients had no observable cardiac or musculo-skeletal deficits. In this case study, a 22-year-old patient underwent surgical repair for scoliosis. Proton MRS of this patient's brain demonstrated the near-absence of creatine and phosphocreatine within the cerebral white and deep gray matter structures. Cerebral atrophy was noted with serial MRI examinations. Subsequent genetic and metabolic analysis showed some biochemical anomalies consistent with a CrT deficiency. The mutation in this patient was identified as a deletion at phenylalanine 107 (delF107). Control muscle biopsies were obtained from archived samples, which had been taken with informed consent during routine muscle biopsies for diagnostic purposes. We determined that the total Cr concentration in the skeletal muscle biopsy was 39.3 +/- 2.94 mmol/kg wet wt., which is not significantly different from non-CrT controls, n = 3 (43.3 +/- 3.57 mmol/kg wet wt.). We conclude that the brain appears to lack the ability to transport creatine when there is a mutation in the CrT gene. However, the muscle utilizes another mechanism for maintaining normal creatine levels. Identifying this alternative creatine-transport mechanism may be useful in treating the neurologic and cognitive impairments of patients with creatine-transporter deficiency.
Mol Genet Metab. 2004 Jul.
Guanidinoacetate and creatine/creatinine levels in controls and patients with urea cycle defects.
Arias A, Garcia-Villoria J, Ribes A.
Instituto de Bioquimica Clinica, Corporacio Sanitaria Clinic, Barcelona, Spain.
We established an analytical methodology for guanidinoacetate and creatine determination by gas chromatography-mass spectrometry with the use of stable isotopes as internal standards. The method showed good precision and high sensitivity, and it requires minimal sample handling. We determined the reference values in urine and plasma. In urine both guanidinoacetate concentration and creatine/creatinine ratio decrease as age increases, but no significant differences were found in plasma. In addition, 15 patients with urea cycle defects were analysed and showed low guanidinoacetate concentrations when compared with age-matched controls. We concluded that guanidinoacetate concentration is a parameter to be considered in the follow-up of patients with urea cycle defects, and arginine should be supplemented in sufficient amounts, as the brain seems to be impermeable to creatine influx, but not to its precursor, arginine, which is needed for creatine, protein, and NO synthesis.
Hum Mol Genet. 2004 May 1.
Severely altered guanidino compound levels, disturbed body weight homeostasis and impaired fertility in a mouse model of guanidinoacetate N-methyltransferase (GAMT) deficiency.
Schmidt A, Marescau B, Boehm EA, Renema WK, Peco R, Das A, Steinfeld R, Chan S, Wallis J, Davidoff M, Ullrich K, Waldschutz R, Heerschap A, De Deyn PP, Neubauer S, Isbrandt D.
Center for Molecular Neurobiology Hamburg (ZMNH), Institute for Neural Signal Transduction, Hamburg, Germany.
[ Free full text ]
We generated a knockout mouse model for guanidinoacetate N-methyltransferase (GAMT) deficiency (MIM 601240), the first discovered human creatine deficiency syndrome, by gene targeting in embryonic stem cells. Disruption of the open reading frame of the murine GAMT gene in the first exon resulted in the elimination of 210 of the 237 amino acids present in mGAMT. The creation of an mGAMT null allele was verified at the genetic, RNA and protein levels. GAMT knockout mice have markedly increased guanidinoacetate (GAA) and reduced creatine and creatinine levels in brain, serum and urine, which are key findings in human GAMT patients. In vivo (31)P magnetic resonance spectroscopy showed high levels of PGAA and reduced levels of creatine phosphate in heart, skeletal muscle and brain. These biochemical alterations were comparable to those found in human GAMT patients and can be attributed to the very similar GAMT expression patterns found by us in human and mouse tissues. We provide evidence that GAMT deficiency in mice causes biochemical adaptations in brain and skeletal muscle. It is associated with increased neonatal mortality, muscular hypotonia, decreased male fertility and a non-leptin-mediated life-long reduction in body weight due to reduced body fat mass. Therefore, GAMT knockout mice are a valuable creatine deficiency model for studying the effects of high-energy phosphate depletion in brain, heart, skeletal muscle and other organs.
Mol Genet Metab. 2004 Apr.
Ammonia toxicity to the brain and creatine.
Bachmann C, Braissant O, Villard AM, Boulat O, Henry H.
Laboratoire Central de Chimie Clinique, Centre Hospitalier Universitaire Vaudois, University of Lausanne, LCC, CHUV, Bugnon 46, 1011 Lausanne, Switzerland.
Symptoms of hyperammonemia are age-dependent and some are reversible. Multiple mechanisms are involved. Hyperammonemia increases the uptake of tryptophan into the brain by activation of the L-system carrier while brain glutamine plays a still undefined role. The uptake of tryptophan by the brain is enhanced when the plasma levels of branched-chain amino acids competing with the other large neutral amino acids are low. Hyperammonemia increases the utilization of branched-chain amino acids in muscle when ketoglutarate is low, and this is further enhanced by glutamine depletion (as a result of therapy with ammonia scavengers like phenylbutyrate). Anorexia, most likely a serotoninergic symptom, might further aggravate the deficiency of indispensable amino acids (e.g., branched-chain and arginine). The role of increased glutamine production in astrocytes and the excitotoxic and metabotropic effects of increased extracellular glutamate have been extensively investigated and found to differ between models of acute and chronic hyperammonemia. Using an in vitro model of cultured embryonic rat brain cell aggregates, we studied the role of creatine in ammonia toxicity. Cultures exposed to ammonia before maturation showed impaired cholinergic axonal growth accompanied by a decrease of creatine and phosphocreatine, a finding not observed in mature cultures. By using different antibodies, we have shown that the phosphorylated form of the intermediate neurofilament protein is affected. Adding creatine to the culture medium partially prevents impairment of axonal growth and the presence of glia in the culture is a precondition for this protective effect. Adequate arginine substitution is essential in the treatment of urea cycle defects as creatine is inefficiently transported into the brain.
Acta Biochim Pol. 2004.
Biochemical and clinical characteristics of creatine deficiency syndromes.
Sykut-Cegielska J, Gradowska W, Mercimek-Mahmutoglu S, Stockler-Ipsiroglu S.
Division of Metabolic Diseases, Department of Pedatrics, Children's Memorial Health Institute, Warsaw, Poland.
[ Free full text ]
Creatine deficiency syndromes are a newly described group of inborn errors of creatine synthesis (arginine:glycine amidinotransferase (AGAT) deficiency and guanidinoacetate methyltransferase (GAMT) deficiency) and of creatine transport (creatine transporter (CRTR) deficiency). The common clinical feature of creatine deficiency syndromes is mental retardation and epilepsy suggesting main involvement of cerebral gray matter. The typical biochemical abnormality of creatine deficiency syndromes is cerebral creatine deficiency, which is demonstrated by in vivo proton magnetic resonance spectroscopy. Measurement of guanidinoacetate in body fluids may discriminate between the GAMT (high concentration), AGAT (low concentration) and CRTR (normal concentration) deficiencies. Further biochemical characteristics include changes in creatine and creatinine concentrations in body fluids. GAMT and AGAT deficiency are treatable by oral creatine supplementation, while patients with CRTR deficiency do not respond to this type of treatment. The creatine deficiency syndromes are underdiagnosed, so their possibility should be considered in all children affected by unexplained mental retardation, seizures and speech delay.
Ann Neurol. 2003 Feb.
Lack of creatine in muscle and brain in an adult with GAMT deficiency.
Schulze A, Bachert P, Schlemmer H, Harting I, Polster T, Salomons GS, Verhoeven NM, Jakobs C, Fowler B, Hoffmann GF, Mayatepek E.
Division of Metabolic and Endocrine Diseases, Department of General Pediatrics, University Children's Hospital, Heidelberg, Germany.
Guanidinoacetate methyltransferase deficiency, which so far has been exclusively detected in children, was diagnosed in a 26-year-old man. The full-blown spectrum of clinical symptoms already had been present since infancy without progression of symptoms during adolescence. Cranial magnetic resonance imaging showed normal findings. Ophthalmological examination showed no retinal changes. Besides creatine deficiency in the brain, a distinct lack of phosphocreatine in skeletal muscle was proved by (31)P magnetic resonance spectroscopy. Creatine substitution combined with a guanidinoacetate-lowering diet introduced first at the age of 26 years was shown to be effective by an impressive improvement of epileptic seizures, mental capabilities, and general behavior and by normalization of the (31)P spectrum in the skeletal muscle.
Mol Cell Biochem. 2003 Feb.
Creatine deficiency syndromes.
Schulze A.
Division of Metabolic and Endocrine Diseases, University Children's Hospital, Heidelberg, Germany.
Since the first description of a creatine deficiency syndrome, the guanidinoacetate methyltransferase (GAMT) deficiency, in 1994, the two further suspected creatine deficiency syndromes--the creatine transporter (CrT1) defect and the arginine:glycine amidinotransferase (AGAT) deficiency were disclosed. GAMT and AGAT deficiency have autosomal-recessive traits, whereas the CrT1 defect is a X-linked disorder. All patients reveal developmental delay/regression, mental retardation, and severe disturbance of their expressive and cognitive speech. The common feature of all creatine deficiency syndromes is the severe depletion of creatine/phosphocreatine in the brain. Only the GAMT deficiency is in addition characterized by accumulation of guanidinoacetic acid in brain and body fluids. Guanidinoacetic acid seems to be responsible for intractable seizures and the movement disorder, both exclusively found in GAMT deficiency. Treatment with oral creatine supplementation is in part successful in GAMT and AGAT deficiency, whereas in CrT1 defect it is not able to replenish creatine in the brain. Treatment of combined arginine restriction and ornithine substitution in GAMT deficiency is capable to decrease guanidinoacetic acid permanently and improves the clinical outcome. The lack of the creatine/phosphocreatine signal in the patient's brain by means of in vivo proton magnetic resonance spectroscopy is the common finding and the diagnostic clue in all three diseases. In AGAT deficiency guanidinoacetic acid is decreased, whereas creatine in blood was found to be normal. On the other hand the CrT1 defect is characterized by an increased concentration of creatine in blood and urine whereas guanidinoacetic acid concentration is normal. The increasing number of patients detected very recently suffering from a creatine deficiency syndrome and the unfavorable outcome highlights the need of further attempts in early recognition of affected individuals and in optimizing its treatment. The study of creatine deficiency syndromes and their comparative consideration contributes to the better understanding of the pathophysiological role of creatine and other guanidino compounds in man.
Mol Cell Biochem. 2003 Feb.
The clinical syndrome of creatine transporter deficiency.
deGrauw TJ, Cecil KM, Byars AW, Salomons GS, Ball WS, Jakobs C.
Division of Neurology, Childrens Hospital Medical Center, Cincinnati, OH, USA.
To describe the clinical, spectroscopic and neuropsychological features of the first family diagnosed with a defect in the creatine transporter. Proton Magnetic Resonance Spectroscopy (MRS) indicated an absence of creatine and phosphocreatine in the brain of a male patient characterized by developmental delay, mild epilepsy and severe expressive language impairment. Subsequent genetic testing revealed a defect in the X-linked creatine transporter (SLC6A8/CT1), with a hemizygous mutation in the patient and a heterozygous mutation for the female carriers. Magnetic resonance imaging and spectroscopy examinations were performed on a 1.5T clinical MR Scanner. Neuropsychological examinations were performed on the index patient and maternal relatives. Preliminary spectroscopy results indicate the disorder prevents transport of creatine and phosphocreatine in the brain of the affected male. However, the skeletal muscle demonstrates the presence of creatine and phosphocreatine which correlates clinically with normal structure and function. Female carriers demonstrated impairments in confrontational naming and verbal memory assessments. This new neurological syndrome is associated with developmental delay, mild epilepsy, severe language impairment. MR Spectroscopy is a non-invasive method for obtaining a preliminary diagnosis of this disorder. Muscle creatine uptake may be normal in this disorder.
J Inherit Metab Dis. 2003.
Clinical characteristics and diagnostic clues in inborn errors of creatine metabolism.
Stromberger C, Bodamer OA, Stockler-Ipsiroglu S.
Department of Radiotherapy and Radiobiology, University Hospital and General Hospital of Vienna, Austria.
Creatine deficiency syndromes are a newly described group of inborn errors of creatine synthesis (arginine:glycine amidinotransferase (AGAT) deficiency and guanidinoaceteate methyltransferase (GAMT) deficiency) and creatine transport (creatine transporter (CRTR) deficiency). The common clinical denominator of creatine deficiency syndromes is mental retardation and epilepsy, suggesting the main involvement of cerebral grey matter (grey matter disease). Patients with GAMT deficiency exhibit a more complex clinical phenotype with dystonic hyperkinetic movement disorder and epilepsy that in some cases is unresponsive to pharmacological treatment. The common biochemical denominator of creatine deficiency syndromes is cerebral creatine deficiency which is demonstrated by in vivo proton magnetic resonance spectroscopy. Measurement of guanidinoacetate in body fluids may discriminate GAMT (high concentration), AGAT (low concentration) and CRTR (normal concentration). Further biochemical characteristics include changes in creatine and creatinine concentrations in body fluids. GAMT and AGAT deficiency are treatable by oral creatine supplementation, while patients with CRTR deficiency do not respond to this type of treatment. Further recognition of patients will be of major importance for the estimation of the frequency, for the understanding of phenotypic variations and for treatment strategies.
J Inherit Metab Dis. 2003.
X-linked creatine transporter defect: an overview.
Salomons GS, van Dooren SJ, Verhoeven NM, Marsden D, Schwartz C, Cecil KM, DeGrauw TJ, Jakobs C.
Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
In 2001 we identified a new inborn error of metabolism caused by a defect in the X-linked creatine transporter SLC6A8 gene mapped at Xq28 (SLC6A8 deficiency, McKusick 300352). An X-linked creatine transporter defect was presumed because of (1) the absence of creatine in the brain as indicated by proton magnetic resonance spectroscopy (MRS); (2) the elevated creatine levels in urine and normal guanidinoacetate levels in plasma, ruling out a creatine biosynthesis defect; (3) the absence of an improvement on creatine supplementation; and (4) the fact that the pedigree suggested an X-linked disease. Our hypothesis was proved by the presence of a hemizygous nonsense mutation in the male index patient and by the impaired creatine uptake by cultured fibroblasts. Currently, at least 7 unrelated families (13 male patients and 13 carriers) with a SLC6A8 deficiency have been identified. Four families come from one metropolitan area. This suggests that SLC6A8 deficiency may have a relatively high incidence. The hallmarks of the disorder are X-linked mental retardation, expressive speech and language delay, epilepsy, developmental delay and autistic behaviour. In approximately 50% of the female carriers, learning disabilities of varying degrees have been noted.
Neuroscience. 2003. (Erratum in: Neuroscience. 2004. Correction of dosage error in abstract and text.)
Creatine protects against the convulsive behavior and lactate production elicited by the intrastriatal injection of methylmalonate.
Royes LF, Fighera MR, Furian AF, Oliveira MS, da Silva LG, Malfatti CR, Schneider PH, Braga AL, Wajner M, Mello CF.
Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil.
Methylmalonic acidemias are metabolic disorders caused by a severe deficiency of methylmalonyl-CoA mutase activity, which are characterized by neurological dysfunction, including convulsions. It has been reported that the accumulating metabolite, L-methylmalonic acid (MMA), inhibits succinate dehydrogenase leading to ATP depletion in vitro, and that the intrastriatal injection of MMA induces convulsions through secondary NMDA receptor stimulation. In this study we investigated the effect of creatine (12.0 mg/kg, i.p.), succinate (1.5 micromol/striatum) and MK-801 (3 nmol/striatum) on the convulsions and on the striatal lactate increase induced by MMA (4.5 micromol/striatum) in rats [corrected]. The effect of creatine on the striatal phosphocreatine content and on MMA-induced phosphocreatine depletion was also evaluated. Creatine, succinate and MK-801 pretreatment decreased the number and duration of convulsive episodes and the lactate increase elicited by MMA. Creatine, but not succinate, prevented the convulsions and the lactate increase induced by the direct stimulation of NMDA receptors. Acute creatine administration increased the total striatal phosphocreatine content and prevented MMA-induced phosphocreatine depletion. Our results suggest that MMA increases lactate production through secondary NMDA receptor activation, and it is proposed that the anticonvulsant effect of creatine against MMA-induced convulsions may be due to an increase in the phosphocreatine content available for metabolic purposes.
J Child Neurol. 2002 Dec.
Inborn errors of creatine metabolism and epilepsy: clinical features, diagnosis, and treatment.
Leuzzi V.
Department of Child Neurology and Psychiatry, University La Sapienza, Rome, Italy.
Creatine metabolism disorders have so far been described at the level of two synthetic steps, guanidinoacetate N-methyltransferase and arginine:glycine amidinotransferase, and at the level of the creatine transporter 1. Guanidinoacetate N-methyltransferase and arginine:glycine amidinotransferase deficiency respond positively to substitutive treatment with creatine monohydrate. Guanidinoacetate N-methyltransferase deficiency results in a severe neurologic disease (age of onset 3 months to 2 years) characterized by developmental arrest, neurologic deterioration, movement disorders, mental retardation, autistic-like behavior, and epilepsy. Severe early-onset epilepsy with pleomorphic seizures is a key symptom of this disorder. Data suggest that in patients with guanidinoacetate N-methyltransferase deficiency, epilepsy and associated electroencephalographic abnormalities are more responsive to creatine supplementation than to conventional antiepilepsy drugs. Arginine:glycine amidinotransferase and creatine transporter 1 mainly present with mental retardation and severe language disorder. All cases of creatine disorders reported to date have been detected by brain proton magnetic resonance spectroscopy, an expensive technique not routinely used in pediatric neurology. A potential diagnostic strategy to select patients for evaluation using proton magnetic resonance spectroscopy is proposed in this review.
Mol Genet Metab. 2002 Dec.
Creatine depletion in a new case with AGAT deficiency: clinical and genetic study in a large pedigree.
Battini R, Leuzzi V, Carducci C, Tosetti M, Bianchi MC, Item CB, Stockler-Ipsiroglu S, Cioni G.
Division of Child Neurology and Psychiatry, IRCCS Stella Maris and University of Pisa, Via dei Giacinti 2, Calambrone Pisa, Italy.
Arginine:glycine amidinotransferase (AGAT, EC 2.1.4.1) deficiency is a recently recognized autosomal recessive inborn error of creatine biosynthesis, characterized by mental retardation and severe language impairment. We extensively investigated a third 5-year-old patient with AGAT deficiency, discovered in the pedigree of the same Italian family as the two index cases. At the age of 2 years he presented with psychomotor and language delay, and autistic-like behavior. Brain MRI was normal, but brain 1H-MRS disclosed brain creatine depletion, which almost completely normalized following creatine monohydrate supplementation. A remarkable clinical improvement paralleled the restoration of brain creatine concentration. AGAT and GAMT (guanidinoacetate:methyltransferase) genes were analyzed in the proband and in 26 relatives, including the two cousins with AGAT deficiency. Sequencing of the proband's AGAT gene disclosed the same homozygous mutation at nt position 9093 converting a tryptophan (TGG) to a stop codon (TAG) at residue 149 (W149X), as already described in the two previously reported cases. The proband's parents and 10 additional subjects of the pedigree were carriers for this mutation. AGAT deficiency was further confirmed by undetectable AGAT activity in the patient's lymphoblasts. Mutation analysis of the GAMT gene revealed a sequence variation in exon 6 (T209M), not in the proband, but in 15 additional subjects from the pedigree. The silent nature of this sequence variation is supported by its homozygosity in one AGAT deficient cousin and in one asymptomatic adult, both with normal GAMT activity.
Neurobiol Dis. 2002 Nov.
Activation of GABA(A) receptors by guanidinoacetate: a novel pathophysiological mechanism.
Neu A, Neuhoff H, Trube G, Fehr S, Ullrich K, Roeper J, Isbrandt D.
Zentrum fur Molekulare Neurobiologie Hamburg, Universitat Hamburg, Germany.
Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessively inherited disorder of creatine biosynthesis. The disease occurs in early life with developmental delay or arrest and several neurological symptoms, e.g., seizures and dyskinesia. Both the deficiency of high-energy phosphates in neurons and the neurotoxic action of the accumulated metabolite guanidinoacetate (GAA) are candidate mechanisms for the pathophysiology of this disease. To examine a potential role of GAA accumulation, we analyzed the electrophysiological responses of neurons induced by GAA application in primary culture and acute murine brain slices. GAA evoked picrotoxin- and bicuculline-sensitive GABA(A) receptor-mediated chloride currents with an EC(50) of 167 microM in cortical neurons. Pathophysiologically relevant GAA concentrations hyperpolarized globus pallidus neurons and reduced their spontaneous spike frequency with an EC(50) of 15.1 microM. Furthermore, GAA acted as a partial agonist at heterologously expressed GABA(A) but not GABA(B) receptors. The interaction of GAA with neuronal GABA(A) receptors represents a candidate mechanism explaining neurological dysfunction in GAMT deficiency
Neuropediatrics. 2002 Oct.
Congenital creatine transporter deficiency.
deGrauw TJ, Salomons GS, Cecil KM, Chuck G, Newmeyer A, Schapiro MB, Jakobs C.
Division of Neurology, Cincinnati Children's Hospital Medical Center and College of Medicine, University of Cincinnati, Ohio, USA.
Background: Two inborn errors of metabolism of creatine synthesis as well as the X-linked creatine transporter (SLC6A8) deficiency have been recognized. This report describes the features of five identified male patients and their female relatives who are carriers of the X-linked creatine transporter deficiency syndrome. Methods: Proton MR spectroscopy was used to recognize creatine deficiency in the patients. Molecular analysis of the SLC6A8 gene was performed, confirming the diagnosis of homozygous males and heterozygous females. Results: We describe four families from a metropolitan area in the U. S. with X-linked creatine transporter deficiency. All affected males present with developmental delay and severe developmental language impairment. Proton MR spectroscopy shows significantly depressed to essentially absent creatine and phosphocreatine in the male patients. Nonsense mutations and amino acid deletions were found in the SLC6A8 gene in the affected families. Conclusion: Creatine transporter deficiency may be a more common X-linked genetic disorder than originally presumed. The affected males exhibit mental retardation with severe expressive language impairment.
Clin Chem. 2002 Oct.
Guanidinoacetate and creatine plus creatinine assessment in physiologic fluids: an effective diagnostic tool for the biochemical diagnosis of arginine:glycine amidinotransferase and guanidinoacetate methyltransferase deficiencies.
Carducci C, Birarelli M, Leuzzi V, Carducci C, Battini R, Cioni G, Antonozzi I.
Dipartimento di Medicina Sperimentale e Patologia, Universita degli Studi di Roma La Sapienza, Viale del Policlinico 155, Rome, Italy.
[ Free full text ]
Background: Disorders of creatine metabolism arise from genetic alterations of arginine:glycine amidinotransferase (AGAT), guanidinoacetate methyltransferase (GAMT), and the creatine transporter. We developed a strategy for the detection of AGAT and GAMT defects by measurement of guanidinoacetate (GAA) and creatine plus creatinine (Cr+Crn) in biological fluids. Methods: Three patients with AGAT deficiency from the same pedigree and their eight relatives, as well as a patient affected by a GAMT defect and his parents were analyzed by a new HPLC procedure in comparison with 90 controls. The method, which uses precolumn derivatization with benzoin, separation with a reversed-phase column, and fluorescence detection, has shown good precision and sensitivity and requires minimal sample handling. Results: In the three AGAT patients, plasma GAA was 0.01-0.04 micro mol/L [mean (SD) for neurologically normal controls was 1.16 (0.59) micromol/L], Cr+Crn was 15-29 micro mol/L [reference limit in our laboratory, 79 (38) micromol/L]. Urinary GAA was 2.4-5.8 micro mol/L [reference, 311 (191) micromol/L], and Cr+Crn was 2.1-3.3 mmol/L [reference, 9.9 (4.1) mmol/L]. We found a smaller decrease in GAA and Cr+Crn in some carriers of an AGAT defect. In the patient with GAMT deficiency, plasma and urine GAA was increased (18.6 and 1783 micromol/L, respectively), and Cr+Crn was decreased in plasma (10.7 micromol/L) and urine (2.1 mmol/L). GAA was increased in the parents' plasmas and in the mother's urine. Conclusion: The assessment of GAA is a new tool for the detection of both GAMT and AGAT deficiencies.
Neuroscience. 2002.
Health implications of creatine: can oral creatine supplementation protect against neurological and atherosclerotic disease?
Wyss M, Schulze A.
Roche Vitamins AG, Biotechnology Department (VFB), Building 203/113A, CH-4070 Basel, Switzerland.
Major achievements made over the last several years have highlighted the important roles of creatine and the creatine kinase reaction in health and disease. Inborn errors of metabolism have been identified in the three main steps involved in creatine metabolism: arginine:glycine amidinotransferase (AGAT), S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase (GAMT), and the creatine transporter. All these diseases are characterized by a lack of creatine and phosphorylcreatine in the brain, and by (severe) mental retardation. Similarly, knockout mice lacking the brain cytosolic and mitochondrial isoenzymes of creatine kinase displayed a slightly increased creatine concentration, but no phosphorylcreatine in the brain. These mice revealed decreased weight gain and reduced life expectancy, disturbed fat metabolism, behavioral abnormalities and impaired learning capacity. Oral creatine supplementation improved the clinical symptoms in both AGAT and GAMT deficiency, but not in creatine transporter deficiency. In addition, creatine supplementation displayed neuroprotective effects in several animal models of neurological disease, such as Huntington's disease, Parkinson's disease, or amyotrophic lateral sclerosis. All these findings pinpoint to a close correlation between the functional capacity of the creatine kinase/phosphorylcreatine/creatine system and proper brain function. They also offer a starting-point for novel means of delaying neurodegenerative disease, and/or for strengthening memory function and intellectual capabilities. Finally, creatine biosynthesis has been postulated as a major effector of homocysteine concentration in the plasma, which has been identified as an independent graded risk factor for atherosclerotic disease. By decreasing homocysteine production, oral creatine supplementation may, thus, also lower the risk for developing, e.g., coronary heart disease or cerebrovascular disease. Although compelling, these results require further confirmation in clinical studies in humans, together with a thorough evaluation of the safety of oral creatine supplementation.
Mol Genet Metab. 2001 Dec.
Improving treatment of guanidinoacetate methyltransferase deficiency: reduction of guanidinoacetic acid in body fluids by arginine restriction and ornithine supplementation.
Schulze A, Ebinger F, Rating D, Mayatepek E.
Department of General Pediatrics, Division of Metabolic and Endocrine Diseases, University Children's Hospital, Im Neuenheimer Feld 150, Heidelberg, Germany.
Guanidinoacetate methyltransferase (GAMT) deficiency (McKusick 601240), an inborn error of creatine biosynthesis, is characterized by creatine depletion and accumulation of guanidinoacetate (GAA) in the brain. Treatment by oral creatine supplementation had no effect on the intractable seizures. Based on the possible role of GAA as an epileptogenic agent, we evaluated a dietary treatment with arginine restriction and ornithine supplementation in order to achieve reduction of GAA. In an 8-year-old Kurdish girl with GAMT deficiency arginine intake was restricted to 15 mg/kg/day (0.4 g natural protein/kg/day) and ornithine was supplemented with 100 mg/kg/day over a period of 14 months. The diet was enriched with 0.4 g/kg/day of arginine-free essential amino acid mixture and creatine treatment remained unchanged (1.1 g/kg/day). Guanidino compounds in blood, urine, and CSF were measured by means of cation-exchange chromatography. The combination of arginine restriction and ornithine supplementation led to a substantial and permanent decrease of arginine without disturbance of nitrogen detoxification. Formation of GAA was effectively reduced after 4 weeks of treatment and sustained thereafter. Biochemical effects were accompanied by a marked clinical improvement. Distinctly reduced epileptogenic activities in electroencephalography accompanied by almost complete disappearance of seizures demonstrates the positive effect of GAA reduction. This indicates for the first time that GAA may exert an important epileptogenic potential in man. Arginine restriction in combination with ornithine supplementation represents a new and rationale therapeutic approach in GAMT deficiency.
Am J Hum Genet. 2001 Nov.
Arginine:glycine amidinotransferase deficiency: the third inborn error of creatine metabolism in humans.
Item CB, Stockler-Ipsiroglu S, Stromberger C, Muhl A, Alessandri MG, Bianchi MC, Tosetti M, Fornai F, Cioni G.
Department of Pediatrics, University Hospital and General Hospital of Vienna, A-1090 Vienna, Austria.
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Arginine:glycine amidinotransferase (AGAT) catalyzes the first step of creatine synthesis, resulting in the formation of guanidinoacetate, which is a substrate for creatine formation. In two female siblings with mental retardation who had brain creatine deficiency that was reversible by means of oral creatine supplementation and had low urinary guanidinoacetate concentrations, AGAT deficiency was identified as a new genetic defect in creatine metabolism. A homozygous G-A transition at nucleotide position 9297, converting a tryptophan codon (TGG) to a stop codon (TAG) at residue 149 (T149X), resulted in undetectable cDNA, as investigated by reverse-transcription PCR, as well as in undetectable AGAT activity, as investigated radiochemically in cultivated skin fibroblasts and in virus-transformed lymphoblasts of the patients. The parents were heterozygous for the mutant allele, with intermediate residual AGAT activities. Recognition and treatment with oral creatine supplements may prevent neurological sequelae in affected patients.
Pharmacol Rev. 2001 Jun.
Clinical pharmacology of the dietary supplement creatine monohydrate.
Persky AM, Brazeau GA.
Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida, USA.
[ Free full text ]
Creatine is a dietary supplement purported to improve exercise performance and increase fat-free mass. Recent research on creatine has demonstrated positive therapeutic results in various clinical applications. The purpose of this review is to focus on the clinical pharmacology and therapeutic application of creatine supplementation. Creatine is a naturally occurring compound obtained in humans from endogenous production and consumption through the diet. When supplemented with exogenous creatine, intramuscular and cerebral stores of creatine and its phosphorylated form, phosphocreatine, become elevated. The increase of these stores can offer therapeutic benefits by preventing ATP depletion, stimulating protein synthesis or reducing protein degradation, and stabilizing biological membranes. Evidence from the exercise literature has shown athletes benefit from supplementation by increasing muscular force and power, reducing fatigue in repeated bout activities, and increasing muscle mass. These benefits have been applied to disease models of Huntington's, Parkinson's, Duchenne muscular dystrophy, and applied clinically in patients with gyrate atrophy, various neuromuscular disorders, McArdle's disease, and congestive heart failure. This review covers the basics of creatine synthesis and transport, proposed mechanisms of action, pharmacokinetics of exogenous creatine administration, creatine use in disease models, side effects associated with use, and issues on product quality.
Am J Hum Genet. 2001 Jun.
X-linked creatine-transporter gene (SLC6A8) defect: a new creatine-deficiency syndrome.
Salomons GS, van Dooren SJ, Verhoeven NM, Cecil KM, Ball WS, Degrauw TJ, Jakobs C.
VU Medical Center, Metabolic Unit, Department of Clinical Chemistry, 1081 HV Amsterdam, The Netherlands.
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We report the first X-linked creatine-deficiency syndrome caused by a defective creatine transporter. The male index patient presented with developmental delay and hypotonia. Proton magnetic-resonance spectroscopy of his brain revealed absence of the creatine signal. However, creatine in urine and plasma was increased, and guanidinoacetate levels were normal. In three female relatives of the index patient, mild biochemical abnormalities and learning disabilities were present, to various extents. Fibroblasts from the index patient contained a hemizygous nonsense mutation in the gene SLC6A8 and were defective in creatine uptake. The three female relatives were heterozygous for this mutation in SLC6A8, which has been mapped to Xq28.
Ann Neurol. 2001 Mar.
Irreversible brain creatine deficiency with elevated serum and urine creatine: a creatine transporter defect?
Cecil KM, Salomons GS, Ball WS Jr, Wong B, Chuck G, Verhoeven NM, Jakobs C, DeGrauw TJ.
Division of Radiology, Children's Hospital Medical Center and the University of Cincinnati, OH, USA.
Recent reports highlight the utility of in vivo magnetic resonance spectroscopy (MRS) techniques to recognize creatine deficiency syndromes affecting the central nervous system (CNS). Reported cases demonstrate partial reversibility of neurologic symptoms upon restoration of CNS creatine levels with the administration of oral creatine. We describe a patient with a brain creatine deficiency syndrome detected by proton MRS that differs from published reports. Metabolic screening revealed elevated creatine in the serum and urine, with normal levels of guanidino acetic acid. Unlike the case with other reported creatine deficiency syndromes, treatment with oral creatine monohydrate demonstrated no observable increase in brain creatine with proton MRS and no improvement in clinical symptoms. In this study, we report a novel brain creatine deficiency syndrome most likely representing a creatine transporter defect.
J Inherit Metab Dis. 2000 Dec.
Plasma creatinine assessment in creatine deficiency: A diagnostic pitfall.
Verhoeven NM, Guerand WS, Struys EA, Bouman AA, van der Knaap MS, Jakobs C.
Department of Clinical Chemistry, University Hospital Vrije Universiteit, Amsterdlam, The Netherlands.
Guanidinoacetate methyltransferase (GAMT) deficiency (creatine deficiency syndrome) is a recently discovered inborn error of creatine biosynthesis. Affected patients have elevated concentrations of guanidino-acetate, the metabolic precursor of creatine, in urine, plasma and cerebrospinal fluid. In addition, urinary creatinine excretion and plasma creatinine concentration are decreased. For biochemical evaluation of patients suspected to suffer from GAMT deficiency, correct quantification of creatinine in plasma is important. Here we report our experience with different quantification techniques. We found that creatinine in plasma from two GAMT-deficient patients appeared normal when measured by the Jaffe method but was decreased when measured enzymatically or by HPLC. The apparently normal levels of creatinine as measured by the Jaffe method were not caused by guanidinoacetate. In urine, the Jaffe method and the enzymatic method gave similar results, indicating that in urine no false elevations of creatinine can be expected. As the Jaffe method is still widely used for routine plasma creatinine measurements, it is important to realize it cannot be used to exclude GAMT deficiency.
Ann Neurol. 2000 Apr.
Mental retardation and behavioral problems as presenting signs of a creatine synthesis defect.
van der Knaap MS, Verhoeven NM, Maaswinkel-Mooij P, Pouwels PJ, Onkenhout W, Peeters EA, Stockler-Ipsiroglu S, Jakobs C.
Department of Child Neurology, Free University Hospital, Amsterdam, The Netherlands.
Recently, 3 patients with a creatine synthesis defect have been described. They presented with developmental regression, extrapyramidal movement abnormalities, and intractable epilepsy, and they improved with treatment of creatine monohydrate. We report 2 unrelated boys with a creatine synthesis defect and nonspecific presenting signs of psychomotor retardation, behavioral problems, and, in 1, mild epilepsy. Metabolic urine screening revealed elevations in all metabolites, expressed as millimoles per mole of creatinine, which suggests decreased creatinine excretion. This finding led to the correct diagnosis. We propose to include the assessment of the overall concentrations of amino acids and organic acids relative to creatinine in routine metabolic urine screening.
Ann Neurol. 2000 Apr.
Reversible brain creatine deficiency in two sisters with normal blood creatine level.
Bianchi MC, Tosetti M, Fornai F, Alessandri' MG, Cipriani P, De Vito G, Canapicchi R.
Neuroradiology Department, S Chiara Hospital, Pisa, Italy.
We describe a new creatine metabolism disorder in 2 young sisters who suffered from mental retardation and severe language delay. Blood examination, investigation of the most common neurometabolic disorders, and brain magnetic resonance imaging were normal. Diagnosis was established only by means of in vivo proton magnetic resonance spectroscopy, which disclosed generalized depletion of creatine in the brain. Creatine monohydrate oral administration led to almost complete brain creatine level restoration along with improvement of the patients' disabilities.
Clin Chim Acta. 2000 Jan 5.
Guanidinoacetate methyltransferase (GAMT) deficiency: non-invasive enzymatic diagnosis of a newly recognized inborn error of metabolism.
Ilas J, Muhl A, Stockler-Ipsiroglu S.
Department of Pediatrics/National Newborn Screening Laboratory, University of Vienna, Austria.
Guanidinoacetate methyltransferase deficiency is a newly recognized inborn error of creatine biosynthesis. Manifestation of neurologic symptoms occurs in infancy and is partly reversible upon oral substitution of creatine. In the first two index patients, enzymatic diagnosis was established in a liver biopsy, and the underlying molecular defect in the GAMT gene has been identified. In order to provide non-invasive biochemical diagnosis, we have developed an enzyme assay based on the formation of radiolabeled creatine from 14C guanidinoacetate and S-adenosylmethionine in concentrated and dialyzed extracts from cultivated skin fibroblasts, Epstein-Barr virus transformed lymphoblasts, and cultivated amniotic cells. Cells were investigated from controls, from 1 index patient with proven GAMT deficiency and from 3 additional patients with clinical and biochemical signs of GAMT deficiency. Separation of 14C guanidinoacetate from 14C creatine in the reaction mixture was accomplished by HPLC on Hypersil ODS column and radioactivity was determined in fractions according to respective UV signals. GAMT activities in control fibroblasts (n = 7), lymphoblasts (n = 8) and in amniotic cells (n = 2) were 0.38-0.56, 0.61-0.84 and 0.38-0.56 nmol/h/mg protein. Apparent Km values were 9.5-14.8 microM for guanidinoacetate and 68-78 microM for S-adenosylmethionine. In the index patient and in the three additional patients at risk, GAMT activity was < 0.1 nmol/h/mg protein. The assay described here allows non-invasive diagnosis of GAMT deficiency in patients at risk.
Metabolism. 1997 Oct.
Guanidino compounds in guanidinoacetate methyltransferase deficiency, a new inborn error of creatine synthesis.
Stockler S, Marescau B, De Deyn PP, Trijbels JM, Hanefeld F.
Department of Pediatric Neurology, University Children's Hospital, Gottingen, Germany.
The first inborn error of creatine metabolism (guanidinoacetate methyltransferase [GAMT] deficiency) has recently been recognized in an infant with progressive extrapyramidal movement disorder. The diagnosis was established by creatine deficiency in the brain as detected by in vivo magnetic resonance spectroscopy and by defective GAMT activity and two mutant GAMT alleles in a liver biopsy. Here, we describe characteristic guanidino-compound patterns in body fluids of this index patient with GAMT deficiency. Concentrations of guanidino compounds (creatine and guanidinoacetate) and creatinine were determined by cation-exchange chromatography and by color reaction with picric acid, respectively, in urine, plasma, and cerebrospinal fluid (CSF). Creatine concentrations were low in plasma, CSF, and urine while guanidinoacetate concentrations were markedly elevated. Daily urinary creatinine excretion was low, whereas creatinine concentrations in random urine samples were not always discriminative. Guanidino compound to creatinine ratios were not informative, as low creatinine concentrations resulted in high values for all determined compounds. During a 22-month period of oral treatment with creatine-monohydrate, plasma and urinary creatine concentrations increased to levels high above the normal range, and daily urinary creatinine excretion-proportional to total body creatine-became normalized. Guanidinoacetate concentrations remained elevated even during additional substitution of ornithine, which inhibits guanidinoacetate synthesis in vitro. The results indicate that GAMT deficiency can be recognized noninvasively by determination of guanidino compounds (creatine and guanidinoacetate) in body fluids. A deficiency of creatine, but not an accumulation of guanidinoacetate, can be corrected by treatment with oral creatine substitution.
J Pediatr. 1997 Oct.
Creatine deficiency syndrome caused by guanidinoacetate methyltransferase deficiency: diagnostic tools for a new inborn error of metabolism.
Schulze A, Hess T, Wevers R, Mayatepek E, Bachert P, Marescau B, Knopp MV, De Deyn PP, Bremer HJ, Rating D.
Department of General Pediatrics, University Children's Hospital, German Cancer Research Center, Heidelberg, Germany.
Hepatic guanidinoacetate methyltransferase deficiency induces a deficiency of creatine/phosphocreatine in muscle and brain and an accumulation of guanidinoacetic acid (GAA), the precursor of creatine. We describe a patient with this defect, a 4-year-old girl with a dystonic-dyskinetic syndrome in addition to developmental delay and therapy-resistant epilepsy. Several methods were used in the diagnosis of the disease: (1) the creatinine excretion in 24-hour urine was significantly lowered, whereas the creatinine concentration in plasma and in randomly collected urine was not strikingly different from control values; (2) the Sakaguchi staining reaction of guanidino compounds in random urine samples indicated an enhanced GAA excretion; (3) GAA excretion measured quantitatively by guanidino compound analysis using an amino acid analyzer was markedly elevated in random urine samples; (4) in vivo 1H magnetic resonance spectroscopy (MRS) revealed a strong depletion of creatine and an accumulation of GAA in brain; (5) in vivo phosphorus 31 MRS showed a strong decrease of the phosphocreatine resonance and a resonance identified as guanidinoacetate phosphate; and (6) in vitro 1H MRS showed an absence of creatine and creatinine resonances in cerebrospinal fluid and the occurrence of GAA in urine. For early detection of this disease, we recommend the Sakaguchi staining reaction of urine from patients with dystonic-dyskinetic syndrome, seizures, and psychomotor retardation. Positive results should result in further investigations including quantitative guanidino compound analysis and both in vivo and in vitro MRS. Although epilepsy was not affected by orally administered creatine (400 to 500 mg/kg per day), this treatment resulted in clinical improvement and an increase of creatine in cerebrospinal fluid and brain tissue.
Pediatr Neurol. 1997 Sep.
Guanidinoacetate methyltransferase deficiency: new clinical features.
Ganesan V, Johnson A, Connelly A, Eckhardt S, Surtees RA.
Neurosciences Unit; Institute of Child Health (UCL) and Great Ormond Street Hospital for Children NHS Trust; London, England.
Guanidinoacetate methyltransferase deficiency is a recently described inborn error of creatine biosynthesis that responds to treatment with oral creatine supplementation. The previously reported clinical features consist of developmental arrest and an extrapyramidal movement disorder. We describe a patient who presented with epilepsy, global developmental delay, and a persistently low plasma creatinine level. The diagnosis was established by measuring urinary guanidinoacetate and by demonstrating absence of the creatine/phosphocreatine peak in the patient's basal ganglia in 1H magnetic resonance spectroscopy. The clinical and biochemical abnormalities responded to creatine replacement.
Lancet. 1996 Sep 21.
Creatine replacement therapy in guanidinoacetate methyltransferase deficiency, a novel inborn error of metabolism.
Stockler S, Hanefeld F, Frahm J.
Department of Paediatric Neurology, University Children's Hospital, Gottingen, Germany.
Background: The creatine/creatine-phosphate system is essential for the storage and transmission of phosphate-bound energy in muscle and brain. In infants, inefficiency or failure of this metabolic pathway can impair the development of motor control and mentation. Methods: We studied and treated an infant with extrapyramidal signs who was shown--by assay for urinary creatinine and by analysis of brain metabolites with use of nuclear magnetic resonance spectra--to have depletion of body and brain creatine, due to inborn deficiency of guanidinoacetate methyltransferase (GAMT). Findings: Long-term oral administration of creatine-monohydrate (4-8 g per day) to this index patient resulted in substantial clinical improvement, disappearance of magnetic resonance (MRI) signal abnormalities in the globus pallidus, and normalisation of slow background activity on the electroencephalogram (EEG). During the 25-month treatment period, both brain and total body creatine concentrations became normal. Interpretation: Oral creatine replacement has proved to be effective in one child with an inborn error of GAMT. It may well be effective in the treatment of other disorders of creatine synthesis.
Am J Hum Genet. 1996 May.
Guanidinoacetate methyltransferase deficiency: the first inborn error of creatine metabolism in man.
Stockler S, Isbrandt D, Hanefeld F, Schmidt B, von Figura K.
Pediatric Nerology, University Children's Hospital Gottingen, Germany.
In two children with an accumulation of guanidinoacetate in brain and a deficiency of creatine in blood, a severe deficiency of guanidinoacetate methyltransferase (GAMT) activity was detected in the liver. Two mutant GAMT alleles were identified that carried a single base substitution within a 5' splice site or a 13-nt insertion and gave rise to four mutant transcripts. Three of the transcripts encode truncated polypeptides that lack a residue known to be critical for catalytic activity of GAMT. Deficiency of GAMT is the first inborn error of creatine metabolism. It causes a severe developmental delay and extrapyramidal symptoms in early infancy and is treatable by oral substitution with creatine.
Pediatr Res. 1994 Sep.
Creatine deficiency in the brain: a new, treatable inborn error of metabolism.
Stockler S, Holzbach U, Hanefeld F, Marquardt I, Helms G, Requart M, Hanicke W, Frahm J.
Kinderklinik, Universitat Gottingen, Germany.
In a patient with extrapyramidal movement disorder and extremely low creatinine concentrations in serum and urine, in vivo proton magnetic resonance spectroscopy disclosed a generalized depletion of creatinine in the brain. Oral substitution of arginine, a substrate for creatine synthesis, resulted in an increase of brain guanidinoacetate as the immediate precursor of creatine but did not elevate cerebral creatine levels. In contrast, oral substitution of creatine-monohydrate led to a significant increase of brain creatine, a decrease of brain guanidinoacetate, and a normalization of creatinine in serum and urine. Phosphorus magnetic resonance spectroscopy of the brain revealed no detectable creatine-phosphate before oral substitution of creatine and a significant increase afterward. Partial restoration of cerebral creatine concentrations was accompanied by improvement of the patient's neurologic symptoms. This is the first report of a patient with complete creatine deficiency in the brain. Magnetic resonance spectroscopy during arginine and creatine treatment point to an inborn error of creatine biosynthesis at the level of guanidinoacetete-methyltransferase.
