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Nasrallah F, Kraoua I, Joncquel-Chevalier Curt M, Bout MA, Taieb SH, Feki M, Khouja N, Briand G, Kaabachi N. Guanidinoacetate methyltransferase (GAMT) deficiency in two Tunisian siblings: clinical and biochemical features. Clin Lab 2012; 58:427-432. [PMID: 22783571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Guanidinoacetate methyltransferase (GAMT) deficiency is a recently described disorder and few cases have been reported to date. As it is a treatable pathology, we seek to contribute to its better understanding, particularly to further elucidate its biochemical diagnosis for early treatment. METHODS The patients, two brothers aged 13 years (P1) and 11 years (P2), have been explored for signs and symptoms suggestive of inborn errors of metabolism. The quantification of creatine (Cr), guanidinoacetate (GAA), and GAMT activity was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS The two brothers presented a similar clinical picture: developmental delay, epilepsy, axial hypotonia, spastic tetraparesis, severe mental and language delay, and autistic behaviour. GAA concentrations were markedly increased in plasma and in urine [2796 and 3342 micromol/mmol creatinine (control range: 4 - 220 micromol/mmol creatinine)/14 and 29 micromol/L (control range: 0.35 - 1.8 micromol/L), respectively] while plasma and urine creatine concentrations were at the lower normal range limit. Activity of GAMT in lymphoblasts was extremely reduced (< 0.01 nmol/mg protein/hour) compared to healthy subjects. GAMT activity was found to be intermediary in patients' parents. CONCLUSIONS It appears that the clinical picture is heterogeneous but should be considered as potential signs of creatine metabolism disorders, however, the biochemical diagnosis is reliable as the enzyme activity is zero in most cases. To date, it is still too early to establish correlations between symptoms and biochemical profile. However, the identification of additional cases of GAMT deficiency should help elucidate such relationships and the progress of patients treated with creatine in conjunction with ornithine supplementation.
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Kolling J, Wyse ATS. Creatine prevents the inhibition of energy metabolism and lipid peroxidation in rats subjected to GAA administration. Metab Brain Dis 2010; 25:331-8. [PMID: 20830606 DOI: 10.1007/s11011-010-9215-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 07/06/2010] [Indexed: 11/30/2022]
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is an inherited neurometabolic disorder, biochemically characterized by the tissue accumulation of guanidinoacetate (GAA). Affected patients present epilepsy and mental retardation whose etiopathogeny is unclear. Previous reports have shown that GAA alters brain energy metabolism and that creatine, which is depleted in patients with GAMT deficiency, can act as a neuroprotector; as such, in the present study we investigated the effect of creatine administration on some of the altered parameters of energy metabolism (complex II, Na(+),K(+)-ATPase and creatine kinase) and lipid peroxidation caused by intrastriatal administration of GAA in adult rats. Animals were pretreated for 7 days with daily intraperitonial administrations of creatine. Subsequently, these animals were divided into two groups: Group 1 (sham group), rats that suffered surgery and received saline; and group 2 (GAA-treated). Thirty min after GAA or saline, the animals were sacrificed and the striatum dissected out. Results showed that the administration of creatine was able to reverse the activities of complex II, Na(+),K(+)-ATPase and creatine kinase, as well as, the levels of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. These findings indicate that the energy metabolism deficit caused by GAA may be prevented by creatine, which probably acts as an antioxidant since it was able to prevent lipid peroxidation. These data may contribute, at least in part, to a better understanding of the mechanisms related to the energy deficit and oxidative stress observed in GAMT deficiency.
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Gordon N. Guanidinoacetate methyltransferase deficiency (GAMT). Brain Dev 2010; 32:79-81. [PMID: 19289269 DOI: 10.1016/j.braindev.2009.01.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 01/13/2009] [Accepted: 01/23/2009] [Indexed: 11/18/2022]
Abstract
An increasing number of disorders of metabolism are becoming amenable to the treatment, and GAMT deficiency is one of them. The symptoms and signs are reviewed, emphasising that delayed language development is a particular feature. Other symptoms include learning disorders, autistic behaviour, epileptic seizures, and movement disorders. The condition is inherited in an autosomal recessive manner, and mutations in the GAMT gene severely affect the activity of guanidinoacetate. The MRI scan shows an increased signal in the globus pallidus, and the diagnosis is confirmed by finding increased guanidinoacetate in the urine and a low plasma creatine. Other methods of diagnosis are discussed. Treatment is based on giving creatine supplementation orally and a low-protein diet with restricted arginine and increased ornithine. This results in improvement of many of the symptoms, especially of the epileptic seizures and the abnormal movements. It is justifiable to consider this condition in any patient with unexplained learning disorders.
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Engelke UFH, Tassini M, Hayek J, de Vries M, Bilos A, Vivi A, Valensin G, Buoni S, Zannolli R, Brussel W, Kremer B, Salomons GS, Veendrick-Meekes MJBM, Kluijtmans LAJ, Morava E, Wevers RA. Guanidinoacetate methyltransferase (GAMT) deficiency diagnosed by proton NMR spectroscopy of body fluids. NMR IN BIOMEDICINE 2009; 22:538-544. [PMID: 19288536 DOI: 10.1002/nbm.1367] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In patients with guanidinoacetate methyltransferase (GAMT) deficiency several parameters may point towards the diagnosis of GAMT deficiency. These include the low levels of creatine and creatinine in urine, the high concentration of guanidinoacetic acid (GAA) in urine and the low levels of creatine and creatinine in the cerebrospinal fluid (CSF). In this study, body fluids from 10 GAMT deficient patients were analysed using (1)H NMR spectroscopy. The urine 1D (1)H NMR spectra of all the patients showed a doublet resonance at 3.98 ppm (pH 2.50) derived from GAA present in high concentration. For this compound, a good recovery and good correlation was found between an LC-MS/MS method and (1)H NMR spectroscopy. In CSF NMR spectra of these patients, the singlet resonances of creatine and creatinine (3.05 and 3.13 ppm, respectively) were absent (normally always present in (1)H NMR spectra of CSF). Due to overlap by other resonances, the doublet of GAA could not be observed. Our data demonstrate that (1)H NMR spectroscopy of urine and CSF can be used to diagnose patients with GAMT deficiency.
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Dhar SU, Scaglia F, Li FY, Smith L, Barshop BA, Eng CM, Haas RH, Hunter JV, Lotze T, Maranda B, Willis M, Abdenur JE, Chen E, O'Brien W, Wong LJC. Expanded clinical and molecular spectrum of guanidinoacetate methyltransferase (GAMT) deficiency. Mol Genet Metab 2009; 96:38-43. [PMID: 19027335 DOI: 10.1016/j.ymgme.2008.10.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/13/2008] [Accepted: 10/13/2008] [Indexed: 11/29/2022]
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is a disorder of creatine biosynthesis, characterized by excessive amounts of guanidinoacetate in body fluids, deficiency of creatine in the brain, and presence of mutations in the GAMT gene. We present here 8 new patients with GAMT deficiency along with their clinical, biochemical and molecular data. The age at diagnosis of our patients ranges from 0 to 14 years. The age of onset of seizures usually ranges from infancy to 3 years. However, one of our patients developed seizures at age 5; progressing to myoclonic epilepsy at age 8 years and another patient has not developed seizures at age 17 years. Five novel mutations were identified: c.37ins26 (p.G13PfsX38), c.403G>T (p.D135Y), c.507_521dup15 (p.C169_S173dup), c.402C>G (p.Y134X) and c.610_611delAGinsGAA (p.R204EfsX63). Six patients had the c.327G>A (last nucleotide of exon 2) splice-site mutation which suggests that this is one of the most common mutations in the GAMT gene, second only to the known Portuguese founder mutation, c.59G>C (p.W20S). Our data suggests that the clinical presentation can be variable and the diagnosis may be overlooked due to unawareness of this disorder. Therefore, GAMT deficiency should be considered in the differential diagnosis of progressive myoclonic epilepsy as well as in unexplained developmental delay or regression with dystonia, even if the patient has no history of seizures. As more patients are reported, the prevalence of GAMT deficiency will become known and guidelines for prenatal diagnosis, newborn screening, presymptomatic testing and treatment, will need to be formulated.
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Braissant O, Henry H. AGAT, GAMT and SLC6A8 distribution in the central nervous system, in relation to creatine deficiency syndromes: a review. J Inherit Metab Dis 2008; 31:230-9. [PMID: 18392746 DOI: 10.1007/s10545-008-0826-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 02/01/2008] [Accepted: 02/05/2008] [Indexed: 11/25/2022]
Abstract
Creatine deficiency syndromes, either due to AGAT, GAMT or SLC6A8 deficiencies, lead to a complete absence, or a very strong decrease, of creatine within the brain, as measured by magnetic resonance spectroscopy. While the mammalian central nervous system (CNS) expresses AGAT, GAMT and SLC6A8, the lack of SLC6A8 in astrocytes around the blood-brain barrier limits the brain capacity to import creatine from the periphery, and suggests that the CNS has to rely mainly on endogenous creatine synthesis through AGAT and GAMT expression. This seems contradictory with SLC6A8 deficiency, which, despite AGAT and GAMT expression, also leads to creatine deficiency in the CNS. We present novel data showing that in cortical grey matter, AGAT and GAMT are expressed in a dissociated way: e.g. only a few cells co-express both genes. This suggests that to allow synthesis of creatine within the CNS, at least for a significant part of it, guanidinoacetate must be transported from AGAT- to GAMT-expressing cells, possibly through SLC6A8. This would explain the creatine deficiency observed in SLC6A8-deficient patients. By bringing together creatine deficiency syndromes, AGAT, GAMT and SLC6A8 distribution in CNS, as well as a synthetic view on creatine and guanidinoacetate levels in the brain, this review presents a comprehensive framework, including new hypotheses, on brain creatine metabolism and transport, both in normal conditions and in case of creatine deficiency.
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Renema WKJ, Kan HE, Heerschap A. Is ATP elevated in patients with GAMT deficiency? AJNR Am J Neuroradiol 2008; 29:214; author reply 214. [PMID: 18024580 DOI: 10.3174/ajnr.a0803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Verbruggen KT, Knijff WA, Soorani-Lunsing RJ, Sijens PE, Verhoeven NM, Salomons GS, Goorhuis-Brouwer SM, van Spronsen FJ. Global developmental delay in guanidionacetate methyltransferase deficiency: differences in formal testing and clinical observation. Eur J Pediatr 2007; 166:921-5. [PMID: 17186272 DOI: 10.1007/s00431-006-0340-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 10/10/2006] [Indexed: 11/26/2022]
Abstract
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.
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Verbruggen KT, Sijens PE, Schulze A, Lunsing RJ, Jakobs C, Salomons GS, van Spronsen FJ. Successful treatment of a guanidinoacetate methyltransferase deficient patient: findings with relevance to treatment strategy and pathophysiology. Mol Genet Metab 2007; 91:294-6. [PMID: 17466557 DOI: 10.1016/j.ymgme.2007.03.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 03/19/2007] [Indexed: 11/28/2022]
Abstract
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.
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Vodopiutz J, Item CB, Häusler M, Korall H, Bodamer OA. Severe speech delay as the presenting symptom of guanidinoacetate methyltransferase deficiency. J Child Neurol 2007; 22:773-4. [PMID: 17641269 DOI: 10.1177/0883073807304015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Guanidinoacetate methyltransferase deficiency typically presents with muscular hypotonia, global developmental delay, extrapyramidal signs, and seizures during infancy and childhood. The authors report a 5-year-old child with guanidinoacetate methyltransferase deficiency who presented with severe speech delay, emphasizing the importance of an early screening for disorders of creatine synthesis and transport in every infant or child with isolated speech delay of unknown cause.
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Almeida LS, Vilarinho L, Darmin PS, Rosenberg EH, Martinez-Muñoz C, Jakobs C, Salomons GS. A prevalent pathogenic GAMT mutation (c.59G>C) in Portugal. Mol Genet Metab 2007; 91:1-6. [PMID: 17336114 DOI: 10.1016/j.ymgme.2007.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Revised: 01/09/2007] [Accepted: 01/10/2007] [Indexed: 11/17/2022]
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency (MIM 601240), an autosomal recessive disorder of creatine biosynthesis, presents with mental retardation, extrapyramidal symptoms, autistic-like behavior and epilepsy. Other hallmarks are cerebral creatine deficiency, increased levels of guanidinoacetate in body fluids and mutations in the GAMT gene. Creatine supplementation partially restores cerebral creatine content. Worldwide, 29 patients have been identified and 15 different mutations have been reported in the GAMT gene. Ten out of these 29 patients are of Portuguese origin. Likely, a founder effect and a high carrier rate in Portugal exist, since in 17 out of the 20 Portuguese alleles the c.59G>C; p.Trp20Ser mutation was found. We investigated the carrier rate of the c.59G>C; p.Trp20Ser mutation in different regions of Portugal and confirmed the pathogenic nature of this missense mutation by transient transfections. Anonymous bloodspots (1002) were screened for the presence of the c.59G>C; p.Trp20Ser mutation by SNaPshot (Single Nucleotide Polymorphism Multiplex Kit). Eight carriers of c.59G>C; p.Trp20Ser were detected of which four are derived from the Archipelagos. This suggests that the carrier rate of the c.59G>C; p.Trp20Ser mutation is relatively high in these islands, as well as in other parts of Portugal. It also implies that newborn screening in these regions is warranted for this treatable disorder.
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Kan HE, Meeuwissen E, van Asten JJ, Veltien A, Isbrandt D, Heerschap A. Creatine uptake in brain and skeletal muscle of mice lacking guanidinoacetate methyltransferase assessed by magnetic resonance spectroscopy. J Appl Physiol (1985) 2007; 102:2121-7. [PMID: 17347380 DOI: 10.1152/japplphysiol.01327.2006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Creatine (Cr) levels in skeletal muscle and brain of a mouse model of Cr deficiency caused by guanidinoacetate methyltransferase absence (GAMT-/-) were studied after Cr supplementation with 2 g.kg body wt-1.day-1 Cr for 35 days. Localized 1H magnetic resonance spectroscopy (MRS) was performed in brain (cerebellum and thalamus/hippocampus) and in hind leg muscle of GAMT-/- mice before and after Cr supplementation and in control (Con) mice. As expected, a signal for Cr was hardly detectable in MR spectra of GAMT-/- mice before Cr supplementation. In the thalamus/hippocampus region of these mice, an increase in N-acetylasparate (NAA) was observed. During Cr administration, Cr levels increased faster in skeletal muscle compared with brain, but this occurred only during the first day of supplementation. Thereafter, Cr levels increased by 0.8 mM/day in all studied locations. After 35 days of Cr supplementation, Cr levels in all locations were higher compared with Con mice on a Cr-free diet and NAA levels normalized. Only because of the repeated MRS measurements performed in this longitudinal Cr supplementation study on GAMT-/- mice were we able to discover the initial faster uptake of Cr in skeletal muscle compared with brain, which may represent muscular Cr uptake independent of Cr transporter expression. Our results can provide the basis for additional experiments to optimize Cr supplementation in GAMT deficiency, as increases in brain Cr are slow in patients after Cr supplementation.
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Bianchi MC, Tosetti M, Battini R, Leuzzi V, Alessandri' MG, Carducci C, Antonozzi I, Cioni G. Treatment monitoring of brain creatine deficiency syndromes: a 1H- and 31P-MR spectroscopy study. AJNR Am J Neuroradiol 2007; 28:548-54. [PMID: 17353334 PMCID: PMC7977852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
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.
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Morris AAM, Appleton RE, Power B, Isherwood DM, Abernethy LJ, Taylor RW, Turnbull DM, Verhoeven NM, Salomons GS, Jakobs C. Guanidinoacetate methyltransferase deficiency masquerading as a mitochondrial encephalopathy. J Inherit Metab Dis 2007; 30:100. [PMID: 17171576 DOI: 10.1007/s10545-006-0478-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 10/26/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
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.
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Stockler S, Schutz PW, Salomons GS. Cerebral creatine deficiency syndromes: clinical aspects, treatment and pathophysiology. Subcell Biochem 2007; 46:149-166. [PMID: 18652076 DOI: 10.1007/978-1-4020-6486-9_8] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Cerebral creatine deficiency syndromes (CCDSs) are a group of inborn errors of creatine metabolism comprising two autosomal recessive disorders that affect the biosynthesis of creatine--i.e. arginine:glycine amidinotransferase deficiency (AGAT; MIM 602360) and guanidinoacetate methyltransferase deficiency (GAMT; MIM 601240)--and an X-linked defect that affects the creatine transporter, SLC6A8 deficiency (SLC6A8; MIM 300036). The biochemical hallmarks of these disorders include cerebral creatine deficiency as detected in vivo by 1H magnetic resonance spectroscopy (MRS) of the brain, and specific disturbances in metabolites of creatine metabolism in body fluids. In urine and plasma, abnormal guanidinoacetic acid (GAA) levels are found in AGAT deficiency (reduced GAA) and in GAMT deficiency (increased GAA). In urine of males with SLC6A8 deficiency, an increased creatine/creatinine ratio is detected. The common clinical presentation in CCDS includes mental retardation, expressive speech and language delay, autistic like behaviour and epilepsy. Treatment of the creatine biosynthesis defects has yielded clinical improvement, while for creatine transporter deficiency, successful treatment strategies still need to be discovered. CCDSs may be responsible for a considerable fraction of children and adults affected with mental retardation of unknown etiology. Thus, screening for this group of disorders should be included in the differential diagnosis of this population. In this review, also the importance of CCDSs for the unravelling of the (patho)physiology of cerebral creatine metabolism is discussed.
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MESH Headings
- Adult
- Amidinotransferases/deficiency
- Animals
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/pathology
- Brain Diseases, Metabolic, Inborn/physiopathology
- Brain Diseases, Metabolic, Inborn/therapy
- Cerebellar Diseases/diagnosis
- Cerebellar Diseases/enzymology
- Cerebellar Diseases/pathology
- Cerebellar Diseases/physiopathology
- Cerebellar Diseases/therapy
- Child
- Child, Preschool
- Creatine/deficiency
- Creatine/metabolism
- Creatinine/metabolism
- Diagnosis, Differential
- Female
- Genetic Diseases, X-Linked/diagnosis
- Genetic Diseases, X-Linked/enzymology
- Genetic Diseases, X-Linked/pathology
- Genetic Diseases, X-Linked/physiopathology
- Genetic Diseases, X-Linked/therapy
- Glycine/analogs & derivatives
- Glycine/metabolism
- Guanidinoacetate N-Methyltransferase/deficiency
- Humans
- Male
- Nerve Tissue Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Syndrome
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Mudd SH, Brosnan JT, Brosnan ME, Jacobs RL, Stabler SP, Allen RH, Vance DE, Wagner C. Methyl balance and transmethylation fluxes in humans. Am J Clin Nutr 2007; 85:19-25. [PMID: 17209172 DOI: 10.1093/ajcn/85.1.19] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Various questions have been raised about labile methyl balance and total transmethylation fluxes, and further discussion has been encouraged. This report reviews and discusses some of the relevant evidence now available. The fact that, if needed, labile methyl balance is maintained by methylneogenesis appears to be established, but several aspects of transmethylation remain uncertain: definitive measurements of the rate of total transmethylation in humans of both sexes on various diets and at various ages; the extent to which synthesis of phosphatidylcholine has been underestimated; and the relative contributions of the 2 pathways for the formation of sarcosine (ie, N-methylglycine). The available evidence indicates that the quantitatively most important pathways for S-adenosylmethionine-dependent transmethylation in mammals are the syntheses of creatine by guanidinoacetate methyltransferase, of phosphatidylcholine by phosphatidylethanolamine methyltransferase, and of sarcosine by glycine N-methyltransferase. Data presented in this report show that S-adenosylmethionine and methionine accumulate abnormally in the plasma of humans with glycine N-methyltransferase deficiency but not of those with guanidinoacetate N-methyltransferase deficiency or in the plasma or livers of mice devoid of phosphatidylethanolamine N-methyltransferase activity. The absence of such accumulations in the latter 2 conditions may be due to removal of S-adenosylmethionine by synthesis of sarcosine. Steps that may help clarify the remaining issues include the determination of the relative rates of synthesis of sarcosine, creatine, and phosphatidylcholine by rapid measurement of the rates of radiolabel incorporation into these compounds from L-[methyl-3H]methionine administered intraportally to an experimental animal; clarification of the intracellular hepatic isotope enrichment value during stable-isotope infusion studies to enhance the certainty of methyl flux estimates during such studies; and definitive measurement of the dietary betaine intake from various diets.
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Abstract
Recent observations in two patients, one with AGAT deficiency (AGAT-D) and one with GAMT deficiency (GAMT-D), both diagnosed already at birth, provide first evidence for important therapeutic effects of pre-symptomatic treatment with creatine (Cr) supplementation in AGAT-D and Cr supplementation plus guanidinoacetate lowering strategies in GAMT-D. Although long-term data are lacking, the results suggest that complete prevention of neurological sequelae in early treated patients could be feasible (Battini et al., 2006; Schulze et al., 2006).
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Almeida LS, Rosenberg EH, Martinez-Muñoz C, Verhoeven NM, Vilarinho L, Jakobs C, Salomons GS. Overexpression of GAMT restores GAMT activity in primary GAMT-deficient fibroblasts. Mol Genet Metab 2006; 89:392-4. [PMID: 16899382 DOI: 10.1016/j.ymgme.2006.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 06/15/2006] [Accepted: 06/15/2006] [Indexed: 10/24/2022]
Abstract
Guanidinoacetate methyltransferase deficiency (MIM 601240) is an autosomal recessive disorder of creatine biosynthesis. Patients present with mental retardation, extrapyramidal symptoms, autistic-like behavior, epilepsy, cerebral creatine deficiency and increased levels of guanidinoacetate. So far 15 mutations have been reported, including six missense variants that are highly likely to be pathogenic mutations. To prove that mutations in the GAMT gene are responsible for GAMT deficiency we overexpressed the GAMT open reading frame in GAMT-deficient fibroblasts by stable transfection. In addition, HeLa cells were transiently transfected with the same expression vector. In contrast to mock transfectants transfection of primary GAMT-deficient fibroblasts with wild-type GAMT results in the restoration of GAMT activity as measured by GC-MS using stable isotope labeled substrates. Moreover, the expression of the GAMT-EGFP fusion protein was analyzed by Western blot, confirming the presence of GAMT fusion protein, both in the stable as well as in the transient transfectants. Here, we prove that mutations in the GAMT gene are responsible for GAMT deficiency, since overexpression of the GAMT open reading frame restores GAMT activity in GAMT-deficient fibroblasts. Furthermore, the transient transfection of HeLa cells will be important for functional analysis of variants of unknown consequence (i.e., missense mutations).
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Schulze A, Hoffmann GF, Bachert P, Kirsch S, Salomons GS, Verhoeven NM, Mayatepek E. Presymptomatic treatment of neonatal guanidinoacetate methyltransferase deficiency. Neurology 2006; 67:719-21. [PMID: 16924036 DOI: 10.1212/01.wnl.0000230152.25203.01] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
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.
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Mercimek-Mahmutoglu S, Stoeckler-Ipsiroglu S, Adami A, Appleton R, Araújo HC, Duran M, Ensenauer R, Fernandez-Alvarez E, Garcia P, Grolik C, Item CB, Leuzzi V, Marquardt I, Mühl A, Saelke-Kellermann RA, Salomons GS, Schulze A, Surtees R, van der Knaap MS, Vasconcelos R, Verhoeven NM, Vilarinho L, Wilichowski E, Jakobs C. GAMT deficiency: Features, treatment, and outcome in an inborn error of creatine synthesis. Neurology 2006; 67:480-4. [PMID: 16855203 DOI: 10.1212/01.wnl.0000234852.43688.bf] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
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.
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Cheillan D, Salomons GS, Acquaviva C, Boisson C, Roth P, Cordier MP, François L, Jakobs C, Vianey-Saban C. Prenatal Diagnosis of Guanidinoacetate Methyltransferase Deficiency: Increased Guanidinoacetate Concentrations in Amniotic Fluid. Clin Chem 2006; 52:775-7. [PMID: 16595836 DOI: 10.1373/clinchem.2005.065185] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Zugno AI, Scherer EBS, Schuck PF, Oliveira DL, Wofchuk S, Wannmacher CMD, Wajner M, Wyse ATS. Intrastriatal administration of guanidinoacetate inhibits Na+, K+-ATPase and creatine kinase activities in rat striatum. Metab Brain Dis 2006; 21:41-50. [PMID: 16773469 DOI: 10.1007/s11011-006-9003-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2005] [Accepted: 09/12/2005] [Indexed: 11/28/2022]
Abstract
Guanidinoacetate methyltransferase deficiency (GAMT deficiency) is an inherited neurometabolic disorder clinically characterized by epilepsy and mental retardation and biochemically by accumulation of guanidinoacetate (GAA) and depletion of creatine. Although this disease is predominantly characterized by severe neurological findings, the underlying mechanisms of brain injury are not yet established. In the present study, we investigated the effect of intrastriatal administration of GAA on Na+, K+-ATPase activity, total (tCK), cytosolic (Cy-CK), and mitochondrial (Mi-CK) creatine kinase (CK) activities in rat striatum. We verified that Na+, K+-ATPase, tCK, and Mi-CK activities were significantly inhibited by GAA, in contrast to Cy-CK which was not affected by this guanidino compound. Since these enzyme activities can be affected by reactive species, we also investigated the effect of intrastriatal administration of GAA on thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation in rats. We found that this metabolite significantly increased this oxidative stress parameter. Considering the importance of Na+, K+-ATPase and CK activities for brain metabolism homeostasis, our results suggest that the inhibition of these enzymes by increased intracerebral levels of GAA may contribute to the neuropathology observed in patients with GAMT-deficiency.
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Carducci C, Santagata S, Leuzzi V, Carducci C, Artiola C, Giovanniello T, Battini R, Antonozzi I. Quantitative determination of guanidinoacetate and creatine in dried blood spot by flow injection analysis-electrospray tandem mass spectrometry. Clin Chim Acta 2006; 364:180-7. [PMID: 16197934 DOI: 10.1016/j.cca.2005.06.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 06/16/2005] [Accepted: 06/17/2005] [Indexed: 11/19/2022]
Abstract
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.
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Boddaert N, Ribeiro M, Touati G, Mention K, Valayanopoulos V, Nihoul-Fékété C, Brunelle F, de Lonlay P. [Radiological innovations in the screening and diagnosis of the inborn errors of metabolism]. Med Sci (Paris) 2005; 21:981-6. [PMID: 16274650 DOI: 10.1051/medsci/20052111981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
New metabolic diseases are regularly identified by a genetic or biochemical approach. Indeed, the metabolic diseases result from an enzymatic block with accumulation of a metabolite upstream to the block and deficit of a metabolite downstream. The characterization of these abnormal metabolites by MRI spectroscopy permitted to identify the deficient enzyme in two new groups of diseases, creatine deficiencies and polyol anomalies. Creatine deficiency is implicated in unspecific mental retardation. A low peak of creatine at MRI spectroscopy is evocating of creatine deficiency which is treatable by creatine administration. Deficiency of synthesis of polyols, metabolites on the pentose pathway, represent new described metabolic diseases with variable symptoms including a neurological distress, liver disease, splenomegaly, cutis laxa and renal insufficiency. The deficit of ribose-5-phosphate isomerase, one of the enzymes whose diagnosis is evoked in front of the accumulation of ribitol, arabitol and xylitol leads to a leucodystrophy in adults. This new deficit was highlighted by the identification of an abnormal peak in cerebral MRI-spectroscopy corresponding to the abnormal accumulation of polyols in brain. Congenital hyperinsulinism (HI) is characterized by profound hypoglycaemia related to inappropriate insulin secretion. Focal and diffuse forms of hyperinsulinism share a similar clinical presentation but their treatment is dramatically different. Until recently, preoperative differential diagnosis was based on pancreatic venous sampling, an invasive and technically demanding technique. Positron emission tomography (PET) after injection of [18F]Fluoro-L-DOPA has been evaluated for the preoperative differentiation between focal and diffuse HI, by imaging uptake of radiotracer and the conversion of [18F]Fluoro-L-DOPA into dopamine by DOPA decarboxylase. PET with [18F]Fluoro-L-DOPA has been validated as a reliable test to differentiate diffuse and focal HI and is now a major differential diagnosis tool in infantile hyperinsulinemic hypoglycaemia.
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Item CB, Stöckler-Ipsiroglu S, Willheim C, Mühl A, Bodamer OA. Use of denaturing HPLC to provide efficient detection of mutations causing guanidinoacetate methyltransferase deficiency. Mol Genet Metab 2005; 86:328-34. [PMID: 16054853 DOI: 10.1016/j.ymgme.2005.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 05/18/2005] [Indexed: 10/25/2022]
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive error of creatine synthesis characterized by cerebral creatine deficiency, accumulation of guanidinoacetate, mental retardation, epilepsy, and extrapyramidal symptoms. To date, 14 mutations of the GAMT gene in 27 patients have been reported. Mutation analysis was done using direct sequencing of PCR products and denaturing gradient gel electrophoresis in combination with direct sequencing. In contrast, we evaluated the efficiency of a newly developed DHPLC method to detect mutations in the GAMT gene by analysing DNA from 14 GAMT patients with known mutations. PCR amplification of both patient and control DNA was followed by formation of homoduplices and heteroduplices, and their detection by DHPLC. DHPLC identified all mutations tested and is the preferred choice of analytical method.
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