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Yıldız Y, Ardıçlı D, Göçmen R, Yalnızoğlu D, Topçu M, Coşkun T, Tokatlı A, Haliloğlu G. Electro-clinical features and long-term outcomes in guanidinoacetate methyltransferase (GAMT) deficiency. Eur J Paediatr Neurol 2024; 49:66-72. [PMID: 38394710 DOI: 10.1016/j.ejpn.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/06/2024] [Accepted: 02/11/2024] [Indexed: 02/25/2024]
Abstract
OBJECTIVE To evaluate clinical characteristics and long-term outcomes in patients with guanidinoacetate methyltransferase (GAMT) deficiency with a special emphasis on seizures and electroencephalography (EEG) findings. METHODS We retrospectively analyzed the clinical and molecular characteristics, seizure types, EEG findings, neuroimaging features, clinical severity scores, and treatment outcomes in six patients diagnosed with GAMT deficiency. RESULTS Median age at presentation and diagnosis were 11.5 months (8-12 months) and 63 months (18 months -11 years), respectively. Median duration of follow-up was 14 years. Global developmental delay (6/6) and seizures (5/6) were the most common symptoms. Four patients presented with febrile seizures. The age at seizure-onset ranged between 8 months and 4 years. Most common seizure types were generalized tonic seizures (n = 4) and motor seizures resulting in drop attacks (n = 3). Slow background activity (n = 5) and generalized irregular sharp and slow waves (n = 3) were the most common EEG findings. Burst-suppression and electrical status epilepticus during slow-wave sleep (ESES) pattern was present in one patient. Three of six patients had drug-resistant epilepsy. Post-treatment clinical severity scores showed improvement regarding movement disorders and epilepsy. All patients were seizure-free in the follow-up. CONCLUSIONS Epilepsy is one of the main symptoms in GAMT deficiency with various seizure types and non-specific EEG findings. Early diagnosis and initiation of treatment are crucial for better seizure and cognitive outcomes. This long-term follow up study highlights to include cerebral creatine deficiency syndromes in the differential diagnosis of patients with global developmental delay and epilepsy and describes the course under treatment.
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Affiliation(s)
- Yılmaz Yıldız
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Metabolism and Nutrition, Turkey.
| | - Didem Ardıçlı
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Neurology, Turkey
| | - Rahşan Göçmen
- Hacettepe University Faculty of Medicine, Department of Radiology, Turkey.
| | - Dilek Yalnızoğlu
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Neurology, Turkey.
| | - Meral Topçu
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Neurology, Turkey
| | - Turgay Coşkun
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Metabolism and Nutrition, Turkey
| | - Ayşegül Tokatlı
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Metabolism and Nutrition, Turkey.
| | - Göknur Haliloğlu
- Hacettepe University Faculty of Medicine, Department of Pediatrics, Division of Pediatric Neurology, Turkey.
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Almaghrabi MA, Muthaffar OY, Alahmadi SA, Abdulsbhan MA, Bamusa M, Aljezani MA, Bahowarth SY, Alyazidi AS, Aggad WS. GAMT Deficiency Among Pediatric Population: Clinical and Molecular Characteristics and Management. Child Neurol Open 2023; 10:2329048X231215630. [PMID: 38020815 PMCID: PMC10655665 DOI: 10.1177/2329048x231215630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/12/2023] [Accepted: 11/03/2023] [Indexed: 12/01/2023] Open
Abstract
Objective: Analyze the treatment modalities used in real practice by synthesizing available literature. Methods: We reviewed and evaluated 52 cases of GAMT deficiency including 4 novel cases from Saudi Arabia diagnosed using whole-exome sequencing. All data utilized graphical presentation in the form of line charts and illustrated graphs. Results: The mean current age of was 117 months (±29.03) (range 12-372 months). The mean age of disease onset was 28.32 months (±13.68) (range 8 days - 252 months). The most prevalent symptom was developmental delays, mainly speech and motor, seizures, and intellectual disability. The male-to-female ratio was 3:1. Multiple treatments were used, with 54 pharmacological interventions, valproic acid being the most common. Creatinine monohydrate was the prevalent dietary intervention, with 25 patients reporting an improvement. Conclusion: The study suggests that efficient treatment with appropriate dietary intervention can improve patients' health, stressing that personalized treatment programs are essential in managing this disorder.
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Affiliation(s)
- Majdah A. Almaghrabi
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osama Y. Muthaffar
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sereen A. Alahmadi
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mashael A. Abdulsbhan
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mashael Bamusa
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maram Ahmed Aljezani
- Division of Pediatrics Neurology, Department of Pediatrics, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Anas S. Alyazidi
- Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Waheeb S. Aggad
- Department of Anatomy, Faculty of Medicine, University of Jeddah, Jeddah, Saudi Arabia
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3
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Lack of Epileptogenic Effects of the Creatine Precursor Guanidinoacetic Acid on Neuronal Cultures In Vitro. Biomolecules 2022; 13:biom13010074. [PMID: 36671459 PMCID: PMC9856136 DOI: 10.3390/biom13010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/19/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
The creatine precursor Guanidinoacetic Acid (GAA) accumulates in the genetic deficiency of the GuanidinoAcetate Methyl Transferase (GAMT) enzyme and it is believed to cause the seizures that often occur in this condition. However, evidence that it is indeed epileptogenic is scarce and we previously found that it does not cause neuronal hyperexcitation in in vitro brain slices. Here, we used Micro-Electrode Arrays (MEAs) to further investigate the electrophysiological effects of its acute and chronic administration in the networks of cultured neurons, either neocortical or hippocampal. We found that: (1) GAA at the 1 µM concentration, comparable to its concentration in normal cerebrospinal fluid, does not modify any of the parameters we investigated in either neuronal type; (2) at the 10 µM concentration, very similar to that found in the GAMT deficiency, it did not affect any of the parameters we tested except the bursting rate of neocortical networks and the burst duration of hippocampal networks, both of which were decreased, a change pointing in a direction opposite to epileptogenesis; (3) at the very high and unphysiological 100 µM concentration, it caused a decrease in all parameters, a change that again goes in the direction opposite to epileptogenesis. Our results confirm that GAA is not epileptogenic.
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Effects of Delivering Guanidinoacetic Acid or Its Prodrug to the Neural Tissue: Possible Relevance for Creatine Transporter Deficiency. Brain Sci 2022; 12:brainsci12010085. [PMID: 35053827 PMCID: PMC8773658 DOI: 10.3390/brainsci12010085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 12/03/2022] Open
Abstract
The creatine precursor guanidinoacetate (GAA) was used as a dietary supplement in humans with no adverse events. Nevertheless, it has been suggested that GAA is epileptogenic or toxic to the nervous system. However, increased GAA content in rodents affected by guanidinoacetate methyltransferase (GAMT) deficiency might be responsible for their spared muscle function. Given these conflicting data, and lacking experimental evidence, we investigated whether GAA affected synaptic transmission in brain hippocampal slices. Incubation with 11.5 μM GAA (the highest concentration in the cerebrospinal fluid of GAMT-deficient patients) did not change the postsynaptic compound action potential. Even 1 or 2 mM had no effect, while 4 mM caused a reversible decrease in the potential. Guanidinoacetate increased creatine and phosphocreatine, but not after blocking the creatine transporter (also used by GAA). In an attempt to allow the brain delivery of GAA when there was a creatine transporter deficiency, we synthesized diacetyl guanidinoacetic acid ethyl ester (diacetyl-GAAE), a lipophilic derivative. In brain slices, 0.1 mM did not cause electrophysiological changes and improved tissue viability after blockage of the creatine transporter. However, diacetyl-GAAE did not increase creatine nor phosphocreatine in brain slices after blockage of the creatine transporter. We conclude that: (1) upon acute administration, GAA is neither epileptogenic nor neurotoxic; (2) Diacetyl-GAAE improves tissue viability after blockage of the creatine transporter but not through an increase in creatine or phosphocreatine. Diacetyl-GAAE might give rise to a GAA–phosphoGAA system that vicariates the missing creatine–phosphocreatine system. Our in vitro data show that GAA supplementation may be safe in the short term, and that a lipophilic GAA prodrug may be useful in creatine transporter deficiency.
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5
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Modi BP, Khan HN, van der Lee R, Wasim M, Haaxma CA, Richmond PA, Drögemöller B, Shah S, Salomons G, van der Kloet FM, Vaz FM, van der Crabben SN, Ross CJ, Wasserman WW, van Karnebeek CD, Awan FR. Adult GAMT deficiency: A literature review and report of two siblings. Mol Genet Metab Rep 2021; 27:100761. [PMID: 33996490 PMCID: PMC8093930 DOI: 10.1016/j.ymgmr.2021.100761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 04/18/2021] [Indexed: 11/02/2022] Open
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is a creatine deficiency disorder and an inborn error of metabolism presenting with progressive intellectual and neurological deterioration. As most cases are identified and treated in early childhood, adult phenotypes that can help in understanding the natural history of the disorder are rare. We describe two adult cases of GAMT deficiency from a consanguineous family in Pakistan that presented with a history of global developmental delay, cognitive impairments, excessive drooling, behavioral abnormalities, contractures and apparent bone deformities initially presumed to be the reason for abnormal gait. Exome sequencing identified a homozygous nonsense variant in GAMT: NM_000156.5:c.134G>A (p.Trp45*). We also performed a literature review and compiled the genetic and clinical characteristics of all adult cases of GAMT deficiency reported to date. When compared to the adult cases previously reported, the musculoskeletal phenotype and the rapidly progressive nature of neurological and motor decline seen in our patients is striking. This study presents an opportunity to gain insights into the adult presentation of GAMT deficiency and highlights the need for in-depth evaluation and reporting of clinical features to expand our understanding of the phenotypic spectrum.
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Affiliation(s)
- Bhavi P. Modi
- Centre for Molecular Medicine and Therapeutics, Dept. of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
- Correspondence to: B. P. Modi, University of British Columbia, BC Children's Hospital Research Institute, 938 W 28 Ave, Vancouver, BC V5Z 4H4, Canada.
| | - Haq Nawaz Khan
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Robin van der Lee
- Centre for Molecular Medicine and Therapeutics, Dept. of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Muhammad Wasim
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Charlotte A. Haaxma
- Department of Pediatric Neurology, Amalia Children's Hospital, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Phillip A. Richmond
- Centre for Molecular Medicine and Therapeutics, Dept. of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Britt Drögemöller
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Suleman Shah
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | - Gajja Salomons
- Laboratory for Genetic Metabolic Diseases, Amsterdam University Medical Centres, Amsterdam, the Netherlands
| | - Frans M. van der Kloet
- Laboratory for Genetic Metabolic Diseases, Amsterdam University Medical Centres, Amsterdam, the Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, the Netherlands
| | - Fred M. Vaz
- Laboratory for Genetic Metabolic Diseases, Amsterdam University Medical Centres, Amsterdam, the Netherlands
- Dept. of Clinical Chemistry and Pediatrics, Amsterdam Gastroenterology Endocrinology Metabolism, University of Amsterdam, the Netherlands
| | | | - Colin J. Ross
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Wyeth W. Wasserman
- Centre for Molecular Medicine and Therapeutics, Dept. of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Clara D.M. van Karnebeek
- Centre for Molecular Medicine and Therapeutics, Dept. of Medical Genetics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
- Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centres, Amsterdam, Netherlands
- Department of Pediatric Metabolic Diseases, Amalia Children's Hospital, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
- United for Metabolic Diseases, the Netherlands
| | - Fazli Rabbi Awan
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
- Correspondence to: F. R. Awan, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad 38000, Pakistan.
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Narayan V, Mahay SB, Verma IC, Puri RD. Case Series of Creatine Deficiency Syndrome due to Guanidinoacetate Methyltransferase Deficiency. Ann Indian Acad Neurol 2020; 23:347-351. [PMID: 32606525 PMCID: PMC7313580 DOI: 10.4103/aian.aian_367_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/02/2018] [Accepted: 12/06/2018] [Indexed: 12/27/2022] Open
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is the second most common defect in the creatine metabolism pathway resulting in cerebral creatine deficiency syndrome (CCDS). We report three patients from two unrelated families, diagnosed with GAMT deficiency on next-generation sequencing. All the probands had happy predisposition as a predominant manifestation in addition to the reported features of global developmental delay, seizures, and microcephaly. This further expands the phenotype of CCDS. The workup for creatine deficiency disorder should be included in the diagnostic algorithm for children with nonsyndromic intellectual disability, especially in those with a happy demeanor. These cases exemplify the utility of magnetic resonance spectroscopy of the brain in the workup of nonsyndromic intellectual disability to diagnose a potentially treatable disorder. In addition, documentation of low serum creatinine may be supportive. Early diagnosis and treatment is essential for better prognosis.
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Affiliation(s)
- Vinu Narayan
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Sunita Bijarnia Mahay
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Ishwar Chander Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
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7
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Almontashiri NAM, Zha L, Young K, Law T, Kellogg MD, Bodamer OA, Peake RWA. Clinical Validation of Targeted and Untargeted Metabolomics Testing for Genetic Disorders: A 3 Year Comparative Study. Sci Rep 2020; 10:9382. [PMID: 32523032 PMCID: PMC7287104 DOI: 10.1038/s41598-020-66401-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/19/2020] [Indexed: 02/04/2023] Open
Abstract
Global untargeted metabolomics (GUM) has entered clinical diagnostics for genetic disorders. We compared the clinical utility of GUM with traditional targeted metabolomics (TM) as a screening tool in patients with established genetic disorders and determined the scope of GUM as a discovery tool in patients with no diagnosis under investigation. We compared TM and GUM data in 226 patients. The first cohort (n = 87) included patients with confirmed inborn errors of metabolism (IEM) and genetic syndromes; the second cohort (n = 139) included patients without diagnosis who were undergoing evaluation for a genetic disorder. In patients with known disorders (n = 87), GUM performed with a sensitivity of 86% (95% CI: 78–91) compared with TM for the detection of 51 diagnostic metabolites. The diagnostic yield of GUM in patients under evaluation with no established diagnosis (n = 139) was 0.7%. GUM successfully detected the majority of diagnostic compounds associated with known IEMs. The diagnostic yield of both targeted and untargeted metabolomics studies is low when assessing patients with non-specific, neurological phenotypes. GUM shows promise as a validation tool for variants of unknown significance in candidate genes in patients with non-specific phenotypes.
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Affiliation(s)
- Naif A M Almontashiri
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Faculty of Applied Medical Sciences and the Center for Genetics and Inherited Disorders, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Li Zha
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kim Young
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Terence Law
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mark D Kellogg
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Olaf A Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of Harvard University and MIT, Cambridge, Massachusetts, USA
| | - Roy W A Peake
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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8
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Identification of β-hydroxybutyrate as a potential biomarker for female papillary thyroid cancer. Bioanalysis 2019; 11:461-470. [PMID: 30892060 DOI: 10.4155/bio-2018-0273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Aim: β-Hydroxybutyrate (BHB) was proved to be a differential metabolite of papillary thyroid cancer (PTC) by semiquantitative analysis, while whether BHB could be used as a potential biomarker for female PTC still needed to be validated. Materials & methods: An LC-MS/MS method with surrogate matrix was established to validate serum BHB in specified PTC patients. Conclusion: Serum BHB levels in PTCs were significantly higher than those in HCs. For both serum BHB with a cut-off value of 312.5 ng/ml and serum BHB/creatinine of 33.5 μmol/mmol, a promising prediction rate to distinguish low-grade PTCs from HCs with satisfactory sensitivity and specificity was achieved, indicating that serum BHB might be proved as a useful biomarker for low-grade female PTC.
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9
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Pajares MA, Pérez-Sala D. Mammalian Sulfur Amino Acid Metabolism: A Nexus Between Redox Regulation, Nutrition, Epigenetics, and Detoxification. Antioxid Redox Signal 2018; 29:408-452. [PMID: 29186975 DOI: 10.1089/ars.2017.7237] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
SIGNIFICANCE Transsulfuration allows conversion of methionine into cysteine using homocysteine (Hcy) as an intermediate. This pathway produces S-adenosylmethionine (AdoMet), a key metabolite for cell function, and provides 50% of the cysteine needed for hepatic glutathione synthesis. The route requires the intake of essential nutrients (e.g., methionine and vitamins) and is regulated by their availability. Transsulfuration presents multiple interconnections with epigenetics, adenosine triphosphate (ATP), and glutathione synthesis, polyol and pentose phosphate pathways, and detoxification that rely mostly in the exchange of substrates or products. Major hepatic diseases, rare diseases, and sensorineural disorders, among others that concur with oxidative stress, present impaired transsulfuration. Recent Advances: In contrast to the classical view, a nuclear branch of the pathway, potentiated under oxidative stress, is emerging. Several transsulfuration proteins regulate gene expression, suggesting moonlighting activities. In addition, abnormalities in Hcy metabolism link nutrition and hearing loss. CRITICAL ISSUES Knowledge about the crossregulation between pathways is mostly limited to the hepatic availability/removal of substrates and inhibitors. However, advances regarding protein-protein interactions involving oncogenes, identification of several post-translational modifications (PTMs), and putative moonlighting activities expand the potential impact of transsulfuration beyond methylations and Hcy. FUTURE DIRECTIONS Increasing the knowledge on transsulfuration outside the liver, understanding the protein-protein interaction networks involving these enzymes, the functional role of their PTMs, or the mechanisms controlling their nucleocytoplasmic shuttling may provide further insights into the pathophysiological implications of this pathway, allowing design of new therapeutic interventions. Antioxid. Redox Signal. 29, 408-452.
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Affiliation(s)
- María A Pajares
- 1 Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas (CSIC) , Madrid, Spain .,2 Molecular Hepatology Group, Instituto de Investigación Sanitaria La Paz (IdiPAZ) , Madrid, Spain
| | - Dolores Pérez-Sala
- 1 Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas (CSIC) , Madrid, Spain
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10
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Sequential chromatin immunoprecipitation to detect SUMOylated MeCP2 in neurons. Biochem Biophys Rep 2016; 5:374-378. [PMID: 28944302 PMCID: PMC5600420 DOI: 10.1016/j.bbrep.2016.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The small ubiquitin-like modifier (SUMO) is a short peptide that can be covalently linked to proteins altering their function. SUMOylation is an essential post-translational modification (PTM). Because of its dynamic nature, low abundance levels, and technical limitations, the occupation of endogenous SUMOylated transcription factors at genomic loci is challenging to detect. The chromatin regulator Methyl CpG binding protein 2 (MeCP2) is subjected to PTMs including SUMO. Mutations in MeCP2 lead to Rett syndrome, a severe neurodevelopmental disorder. Here, we present an efficient method to perform sequential chromatin immunoprecipitation (Seq-ChIP) for detecting SUMOylated MeCP2 in neurons. This Seq-ChIP technique is a useful tool to determine the occupancy of SUMOylated transcription and chromatin factors at specific genomic regions. SUMO is a short peptide that can be covalently linked to proteins. SUMOylation is an essential post-translational modification. MeCP2 is a chromatin regulator whose mutations lead to Rett syndrome. Methodology to detect SUMOylated MeCP2 at specific genomic regions in neurons.
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11
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Mercimek-Mahmutoglu S, Pop A, Kanhai W, Fernandez Ojeda M, Holwerda U, Smith D, Loeber JG, Schielen PCJI, Salomons GS. A pilot study to estimate incidence of guanidinoacetate methyltransferase deficiency in newborns by direct sequencing of the GAMT gene. Gene 2015; 575:127-31. [PMID: 26319512 DOI: 10.1016/j.gene.2015.08.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/21/2015] [Accepted: 08/23/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND GAMT deficiency is an autosomal recessive disorder of creatine biosynthesis causing developmental delays or intellectual disability in untreated patients as a result of irreversible brain damage occurring prior to diagnosis. Normal neurodevelopmental outcome has been reported in patients treated from neonatal period highlighting the importance of early treatment. METHODS Five hundred anonymized newborns from the National Newborn Screening Program of The Netherlands were included into this pilot study. Direct sequencing of the coding region of the GAMT gene was applied following DNA extraction. The disease causing nature of novel missense variants in the GAMT gene was studied by overexpression studies. GAA and creatine was measured in blood dot spots. RESULTS We detected two carriers, one with a known common (c.327G>A) and one with a novel mutation (c.297_309dup (p.Arg105Glyfs*) in the GAMT gene. The estimated incidence of GAMT deficiency was 1:250,000. We also detected five novel missense variants. Overexpression of these variants in GAMT deficient fibroblasts did restore GAMT activity and thus all were considered rare, but not disease causing variants including the c.131G>T (p.Arg44Leu) variant. Interestingly, this variant was predicted to be pathogenic by in silico analysis. The variants were included in the Leiden Open Variation Database (LOVD) database (www.LOVD.nl/GAMT). The average GAA level was 1.14μmol/L±0.45 standard deviations. The average creatine level was 408μmol/L±106. The average GAA/creatine ratio was 2.94±0.136. CONCLUSION The estimated incidence of GAMT deficiency is 1:250,000 newborns based on our pilot study. The newborn screening for GAMT deficiency should be implemented to identify patients at the asymptomatic stage to achieve normal neurodevelopmental outcome for this treatable neurometabolic disease. Biochemical investigations including GAA, creatine and GAMT enzyme activity measurements are essential to confirm the diagnosis of GAMT deficiency. According to availability, all missense variants can be assessed functionally, as in silico prediction analysis of missense variants is not sufficient to confirm the pathogenicity of missense variants.
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Affiliation(s)
- S Mercimek-Mahmutoglu
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, Canada; Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada.
| | - A Pop
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands
| | - W Kanhai
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands
| | - M Fernandez Ojeda
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands
| | - U Holwerda
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands
| | - D Smith
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands
| | - J G Loeber
- National Institute for Public Health and the Environment, Centre for Infectious Diseases Research, and Screening, Bilthoven, The Netherlands
| | - P C J I Schielen
- National Institute for Public Health and the Environment, Centre for Infectious Diseases Research, and Screening, Bilthoven, The Netherlands
| | - G S Salomons
- Metabolic Unit, Department of Clinical Chemistry, VU Medical Center, Neurosciences Campus, Amsterdam, The Netherlands.
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12
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Foo YL, Chow JC, Lai MC, Tsai WH, Tung LC, Kuo MC, Lin SJ. Genetic Evaluation of Children with Global Developmental Delay--Current Status of Network Systems in Taiwan. Pediatr Neonatol 2015; 56:213-9. [PMID: 25454079 DOI: 10.1016/j.pedneo.2014.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 07/30/2014] [Accepted: 08/11/2014] [Indexed: 12/20/2022] Open
Abstract
This review article aims to introduce the screening and referral network of genetic evaluation for children with developmental delay in Taiwan. For these children, integrated systems provide services from the medical, educational, and social welfare sectors. All cities and counties in Taiwan have established a network for screening, detection, referral, evaluation, and intervention services. Increased awareness improves early detection and intervention. There remains a gap between supply and demand, especially with regard to financial resources and professional manpower. Genetic etiology has a major role in prenatal causes of developmental delay. A summary of reports on some related genetic disorders in the Taiwanese population is included in this review. Genetic diagnosis allows counseling with regard to recurrence risk and prevention. Networking with neonatal screening, laboratory diagnosis, genetic counseling, and orphan drugs logistics systems can provide effective treatment for patients. In Taiwan, several laboratories provide genetic tests for clinical diagnosis. Accessibility to advanced expensive tests such as gene chips or whole exome sequencing is limited because of funding problems; however, the service system in Taiwan can still operate in a relatively cost-effective manner. This experience in Taiwan may serve as a reference for other countries.
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Affiliation(s)
- Yong-Lin Foo
- Division of Pediatric Neurology, Department of Pediatrics, Chi Mei Foundation Hospital, Tainan 710, Taiwan
| | - Julie Chi Chow
- Division of Pediatric Neurology, Department of Pediatrics, Chi Mei Foundation Hospital, Tainan 710, Taiwan
| | - Ming-Chi Lai
- Division of Pediatric Neurology, Department of Pediatrics, Chi Mei Foundation Hospital, Tainan 710, Taiwan
| | - Wen-Hui Tsai
- Genetic Counseling Center, Chi Mei Foundation Hospital, Tainan 710, Taiwan
| | - Li-Chen Tung
- Department of Physical Medicine and Rehabilitation, Chi Mei Medical Center, Tainan 710, Taiwan
| | - Mei-Chin Kuo
- Division of Pediatric Neurology, Department of Pediatrics, Chi Mei Foundation Hospital, Tainan 710, Taiwan; Genetic Counseling Center, Chi Mei Foundation Hospital, Tainan 710, Taiwan
| | - Shio-Jean Lin
- Department of Physical Medicine and Rehabilitation, Chi Mei Medical Center, Tainan 710, Taiwan.
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13
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Clark JF, Cecil KM. Diagnostic methods and recommendations for the cerebral creatine deficiency syndromes. Pediatr Res 2015; 77:398-405. [PMID: 25521922 DOI: 10.1038/pr.2014.203] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/15/2014] [Indexed: 12/29/2022]
Abstract
Primary care pediatricians and a variety of specialist physicians strive to define an accurate diagnosis for children presenting with impairment of expressive speech and delay in achieving developmental milestones. Within the past two decades, a group of disorders featuring this presentation have been identified as cerebral creatine deficiency syndromes (CCDS). Patients with these disorders were initially discerned using proton magnetic resonance spectroscopy of the brain within a magnetic resonance imaging (MRI) examination. The objective of this review is to provide the clinician with an overview of the current information available on identifying and treating these conditions. We explain the salient features of creatine metabolism, synthesis, and transport required for normal development. We propose diagnostic approaches for confirming a CCDS diagnosis. Finally, we describe treatment approaches for managing patients with these conditions.
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Affiliation(s)
- Joseph F Clark
- Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Kim M Cecil
- 1] Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio [2] Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio [3] Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio [4] Department of Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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14
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Clinical Presentation and Microarray Analysis of Peruvian Children with Atypical Development and/or Aberrant Behavior. GENETICS RESEARCH INTERNATIONAL 2014; 2014:408516. [PMID: 25400949 PMCID: PMC4221906 DOI: 10.1155/2014/408516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 10/01/2014] [Indexed: 11/21/2022]
Abstract
We report our experience with high resolution microarray analysis in infants and young children with developmental disability and/or aberrant behavior enrolled at the Centro Ann Sullivan del Peru in Lima, Peru, a low income country. Buccal cells were collected with cotton swabs from 233 participants for later DNA isolation and identification of copy number variation (deletions/duplications) and regions of homozygosity (ROH) for estimating consanguinity status in 15 infants and young children (12 males, 3 females; mean age ± SD = 28.1 m ± 7.9 m; age range 14 m–41 m) randomly selected for microarray analysis. An adequate DNA yield was found in about one-half of the enrolled participants. Ten participants showed deletions or duplications containing candidate genes reported to impact behavior or cognitive development. Five children had ROHs which could have harbored recessive gene alleles contributing to their clinical presentation. The coefficient of inbreeding was calculated and three participants showed first-second cousin relationships, indicating consanguinity. Our preliminary study showed that DNA isolated from buccal cells using cotton swabs was suboptimal, but yet in a subset of participants the yield was adequate for high resolution microarray analysis and several genes were found that impact development and behavior and ROHs identified to determine consanguinity status.
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15
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Moeschler JB, Shevell M. Comprehensive evaluation of the child with intellectual disability or global developmental delays. Pediatrics 2014; 134:e903-18. [PMID: 25157020 PMCID: PMC9923626 DOI: 10.1542/peds.2014-1839] [Citation(s) in RCA: 329] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Global developmental delay and intellectual disability are relatively common pediatric conditions. This report describes the recommended clinical genetics diagnostic approach. The report is based on a review of published reports, most consisting of medium to large case series of diagnostic tests used, and the proportion of those that led to a diagnosis in such patients. Chromosome microarray is designated as a first-line test and replaces the standard karyotype and fluorescent in situ hybridization subtelomere tests for the child with intellectual disability of unknown etiology. Fragile X testing remains an important first-line test. The importance of considering testing for inborn errors of metabolism in this population is supported by a recent systematic review of the literature and several case series recently published. The role of brain MRI remains important in certain patients. There is also a discussion of the emerging literature on the use of whole-exome sequencing as a diagnostic test in this population. Finally, the importance of intentional comanagement among families, the medical home, and the clinical genetics specialty clinic is discussed.
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16
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van de Kamp JM, Mancini GM, Salomons GS. X-linked creatine transporter deficiency: clinical aspects and pathophysiology. J Inherit Metab Dis 2014; 37:715-33. [PMID: 24789340 DOI: 10.1007/s10545-014-9713-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/27/2014] [Accepted: 04/01/2014] [Indexed: 12/22/2022]
Abstract
Creatine transporter deficiency was discovered in 2001 as an X-linked cause of intellectual disability characterized by cerebral creatine deficiency. This review describes the current knowledge regarding creatine metabolism, the creatine transporter and the clinical aspects of creatine transporter deficiency. The condition mainly affects the brain while other creatine requiring organs, such as the muscles, are relatively spared. Recent studies have provided strong evidence that creatine synthesis also occurs in the brain, leading to the intriguing question of why cerebral creatine is deficient in creatine transporter deficiency. The possible mechanisms explaining the cerebral creatine deficiency are discussed. The creatine transporter knockout mouse provides a good model to study the disease. Over the past years several treatment options have been explored but no treatment has been proven effective. Understanding the pathogenesis of creatine transporter deficiency is of paramount importance in the development of an effective treatment.
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MESH Headings
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/drug therapy
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/pathology
- Animals
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/physiopathology
- Creatine/deficiency
- Creatine/genetics
- Genetic Diseases, X-Linked/genetics
- Humans
- Intellectual Disability/etiology
- Intellectual Disability/genetics
- Membrane Transport Proteins/deficiency
- Membrane Transport Proteins/genetics
- Mental Retardation, X-Linked/complications
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/physiopathology
- Mice
- Plasma Membrane Neurotransmitter Transport Proteins/deficiency
- Plasma Membrane Neurotransmitter Transport Proteins/genetics
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Affiliation(s)
- Jiddeke M van de Kamp
- Department of Clinical Genetics, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands,
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Mercimek-Mahmutoglu S, Ndika J, Kanhai W, de Villemeur TB, Cheillan D, Christensen E, Dorison N, Hannig V, Hendriks Y, Hofstede FC, Lion-Francois L, Lund AM, Mundy H, Pitelet G, Raspall-Chaure M, Scott-Schwoerer JA, Szakszon K, Valayannopoulos V, Williams M, Salomons GS. Thirteen new patients with guanidinoacetate methyltransferase deficiency and functional characterization of nineteen novel missense variants in the GAMT gene. Hum Mutat 2014; 35:462-9. [PMID: 24415674 DOI: 10.1002/humu.22511] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 01/06/2014] [Indexed: 11/08/2022]
Abstract
Guanidinoacetate methyltransferase deficiency (GAMT-D) is an autosomal recessively inherited disorder of creatine biosynthesis. Creatine deficiency on cranial proton magnetic resonance spectroscopy, and elevated guanidinoacetate levels in body fluids are the biomarkers of GAMT-D. In 74 patients, 50 different mutations in the GAMT gene have been identified with missense variants being the most common. Clinical and biochemical features of the patients with missense variants were obtained from their physicians using a questionnaire. In 20 patients, 17 missense variants, 25% had a severe, 55% a moderate, and 20% a mild phenotype. The effect of these variants on GAMT enzyme activity was overexpressed using primary GAMT-D fibroblasts: 17 variants retained no significant activity and are therefore considered pathogenic. Two additional variants, c.22C>A (p.Pro8Thr) and c.79T>C (p.Tyr27His) (the latter detected in control cohorts) are in fact not pathogenic as these alleles restored GAMT enzyme activity, although both were predicted to be possibly damaging by in silico analysis. We report 13 new patients with GAMT-D, six novel mutations and functional analysis of 19 missense variants, all being included in our public LOVD database. Our functional assay is important for the confirmation of the pathogenicity of identified missense variants in the GAMT gene.
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Affiliation(s)
- Saadet Mercimek-Mahmutoglu
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Canada; Metabolic Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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18
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Stockler-Ipsiroglu S, van Karnebeek C, Longo N, Korenke GC, Mercimek-Mahmutoglu S, Marquart I, Barshop B, Grolik C, Schlune A, Angle B, Araújo HC, Coskun T, Diogo L, Geraghty M, Haliloglu G, Konstantopoulou V, Leuzzi V, Levtova A, Mackenzie J, Maranda B, Mhanni AA, Mitchell G, Morris A, Newlove T, Renaud D, Scaglia F, Valayannopoulos V, van Spronsen FJ, Verbruggen KT, Yuskiv N, Nyhan W, Schulze A. Guanidinoacetate methyltransferase (GAMT) deficiency: outcomes in 48 individuals and recommendations for diagnosis, treatment and monitoring. Mol Genet Metab 2014; 111:16-25. [PMID: 24268530 DOI: 10.1016/j.ymgme.2013.10.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/29/2013] [Accepted: 10/29/2013] [Indexed: 11/25/2022]
Abstract
We collected data on 48 patients from 38 families with guanidinoacetate methyltransferase (GAMT) deficiency. Global developmental delay/intellectual disability (DD/ID) with speech/language delay and behavioral problems as the most affected domains was present in 44 participants, with additional epilepsy present in 35 and movement disorder in 13. Treatment regimens included various combinations/dosages of creatine-monohydrate, l-ornithine, sodium benzoate and protein/arginine restricted diets. The median age at treatment initiation was 25.5 and 39 months in patients with mild and moderate DD/ID, respectively, and 11 years in patients with severe DD/ID. Increase of cerebral creatine and decrease of plasma/CSF guanidinoacetate levels were achieved by supplementation with creatine-monohydrate combined with high dosages of l-ornithine and/or an arginine-restricted diet (250 mg/kg/d l-arginine). Therapy was associated with improvement or stabilization of symptoms in all of the symptomatic cases. The 4 patients treated younger than 9 months had normal or almost normal developmental outcomes. One with inconsistent compliance had a borderline IQ at age 8.6 years. An observational GAMT database will be essential to identify the best treatment to reduce plasma guanidinoacetate levels and improve long-term outcomes.
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Affiliation(s)
| | - Clara van Karnebeek
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada; Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Nicola Longo
- Division of Medical Genetics, University of Utah, Salt Lake City, UT, USA
| | | | | | - Iris Marquart
- Department of Pediatric Neurology, Children's Hospital Oldenburg, Germany
| | - Bruce Barshop
- Department of Pediatrics, University of California, San Diego, CA, USA
| | - Christiane Grolik
- Department of Pediatric Neurology, Children's Hospital Cologne, Germany
| | - Andrea Schlune
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Brad Angle
- Division of Birth Defects and Metabolism, Children's Memorial Hospital, Chicago, IL, USA
| | | | - Turgay Coskun
- Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Luisa Diogo
- Pediatric Hospital CHUC-EPE, Coimbra, Portugal
| | - Michael Geraghty
- Department of Pediatrics, CHEO, University of Ottawa, Ottawa, ON, Canada
| | | | | | - Vincenzo Leuzzi
- Department of Pediatrics, Child Neurology and Psychiatry, La Sapienza University of Rome, Rome, Italy
| | - Alina Levtova
- Department of Pediatrics, Sainte Justine University Hospital Centre, Montreal, QC, Canada
| | | | - Bruno Maranda
- Division of Genetics, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Aizeddin A Mhanni
- Department of Pediatrics and Child Health, University of Mannitoba, Winnipeg, MB, Canada
| | - Grant Mitchell
- Department of Pediatrics, Sainte Justine University Hospital Centre, Montreal, QC, Canada; Sainte Justine University Research Center, Montreal, QC, Canada
| | - Andrew Morris
- Department of Genetic Medicine, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Theresa Newlove
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Deborah Renaud
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Vassili Valayannopoulos
- Reference Center for Inborn Errors of Metabolism, Hopital Necker Enfants Malades, Paris, France
| | - Francjan J van Spronsen
- Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, The Netherlands
| | - Krijn T Verbruggen
- Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, The Netherlands
| | - Nataliya Yuskiv
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - William Nyhan
- Department of Pediatrics, University of California, San Diego, CA, USA
| | - Andreas Schulze
- Department of Pediatrics, The Hospital for Sick Children, University of Toronto, ON, Canada; Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
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19
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Viau KS, Ernst SL, Pasquali M, Botto LD, Hedlund G, Longo N. Evidence-based treatment of guanidinoacetate methyltransferase (GAMT) deficiency. Mol Genet Metab 2013; 110:255-62. [PMID: 24071436 DOI: 10.1016/j.ymgme.2013.08.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 08/30/2013] [Accepted: 08/31/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Guanidinoacetate methyltransferase (GAMT) deficiency causes cerebral creatine deficiency. Patients can have autistic behavior, seizures, intellectual disability, and severe speech delay. The goal of therapy is to increase creatine while reducing potentially neurotoxic guanidinoacetate concentrations. Here we evaluate how different therapies affect plasma guanidinoacetate levels in patients with GAMT deficiency. METHODS Retrospective analysis of data from five new patients with GAMT deficiency (four with delays and seizures, one diagnosed at birth). RESULTS The four symptomatic patients had decreased brain creatine by magnetic resonance spectroscopy and three also had abnormal globi pallidi by MRI. GAMT sequencing identified four previously reported mutations and one novel missense mutation (c.233T>A/p.V78E). Treatment with creatine (250-1000 mg/kg/day), ornithine (100-800 mg/kg/day), and sodium benzoate (50-135 mg/kg/day) supplements along with dietary protein restriction (0.8-1.5 g/kg/day) improved seizures and development with all patients becoming verbal. The patient treated at birth remains developmentally normal. Reduction in glycine and increase in ornithine levels significantly decreased plasma guanidinoacetate, with glycine levels being the best predictor of guanidinoacetate levels. In contrast, arginine levels were not significantly correlated with plasma guanidinoacetate. CONCLUSIONS Our results show that supplements of creatine, sodium benzoate (to reduce glycine) and ornithine reduce guanidinoacetate levels in patients with GAMT deficiency (dietary therapy was not evaluated in our study). Normal development with early therapy renders GAMT deficiency an ideal candidate for inclusion in newborn screening panels.
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Affiliation(s)
- Krista S Viau
- Department of Pediatrics, Division of Medical Genetics, University of Utah, 50 North Mario Capecchi Drive, 2C412 SOM, Salt Lake City, UT 84132, USA.
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20
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Akiyama T, Osaka H, Shimbo H, Nakajiri T, Kobayashi K, Oka M, Endoh F, Yoshinaga H. A Japanese adult case of guanidinoacetate methyltransferase deficiency. JIMD Rep 2013; 12:65-9. [PMID: 23846910 DOI: 10.1007/8904_2013_245] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/12/2013] [Accepted: 05/26/2013] [Indexed: 01/13/2023] Open
Abstract
Guanidinoacetate methyltransferase (GAMT) deficiency is a rare disorder of creatine synthesis resulting in cerebral creatine depletion. We present a 38-year-old patient, the first Japanese case of GAMT deficiency. Developmental delay started after a few months of age with a marked delay in language, which resulted in severe intellectual deficit. She showed hyperactivity and trichotillomania from childhood. Epileptic seizures appeared at 18 months and she had multiple types of seizures including epileptic spasms, brief tonic seizures, atypical absences, complex partial seizures with secondary generalization, and "drop" seizures. They have been refractory to multiple antiepileptic drugs. Although there have been no involuntary movements, magnetic resonance imaging revealed T2 hyperintense lesions in bilateral globus pallidi. Motor regression started around 30 years of age and the patient is now able to walk for only short periods. Very low serum creatinine levels measured by enzymatic method raised a suspicion of GAMT deficiency, which was confirmed by proton magnetic resonance spectroscopy and urinary guanidinoacetate assay. GAMT gene analysis revealed that the patient is a compound heterozygote of c.578A>G, p.Gln193Arg and splice site mutation, c.391G>C, p.Gly131Arg, neither of which have been reported in the literature. We also identified two aberrant splice products from the patient's cDNA analysis. The patient was recently started on supplementation of high-dose creatine and ornithine, the effects of which are currently under evaluation. Although rare, patients with developmental delay, epilepsy, behavioral problems, and movement disorders should be vigorously screened for GAMT deficiency, as it is a treatable disorder.
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Affiliation(s)
- Tomoyuki Akiyama
- Department of Child Neurology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan,
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21
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Cheillan D, Curt MJC, Briand G, Salomons GS, Mention-Mulliez K, Dobbelaere D, Cuisset JM, Lion-François L, Portes VD, Chabli A, Valayannopoulos V, Benoist JF, Pinard JM, Simard G, Douay O, Deiva K, Afenjar A, Héron D, Rivier F, Chabrol B, Prieur F, Cartault F, Pitelet G, Goldenberg A, Bekri S, Gerard M, Delorme R, Tardieu M, Porchet N, Vianey-Saban C, Vamecq J. Screening for primary creatine deficiencies in French patients with unexplained neurological symptoms. Orphanet J Rare Dis 2012; 7:96. [PMID: 23234264 PMCID: PMC3552865 DOI: 10.1186/1750-1172-7-96] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 12/07/2012] [Indexed: 12/11/2022] Open
Abstract
A population of patients with unexplained neurological symptoms from six major French university hospitals was screened over a 28-month period for primary creatine disorder (PCD). Urine guanidinoacetate (GAA) and creatine:creatinine ratios were measured in a cohort of 6,353 subjects to identify PCD patients and compile their clinical, 1H-MRS, biochemical and molecular data. Six GAMT [N-guanidinoacetatemethyltransferase (EC 2.1.1.2)] and 10 X-linked creatine transporter (SLC6A8) but no AGAT (GATM) [L-arginine/glycine amidinotransferase (EC 2.1.4.1)] deficient patients were identified in this manner. Three additional affected sibs were further identified after familial inquiry (1 brother with GAMT deficiency and 2 brothers with SLC6A8 deficiency in two different families). The prevalence of PCD in this population was 0.25% (0.09% and 0.16% for GAMT and SLC6A8 deficiencies, respectively). Seven new PCD-causing mutations were discovered (2 nonsense [c.577C > T and c.289C > T] and 1 splicing [c.391 + 15G > T] mutations for the GAMT gene and, 2 missense [c.1208C > A and c.926C > A], 1 frameshift [c.930delG] and 1 splicing [c.1393-1G > A] mutations for the SLC6A8 gene). No hot spot mutations were observed in these genes, as all the mutations were distributed throughout the entire gene sequences and were essentially patient/family specific. Approximately one fifth of the mutations of SLC6A8, but not GAMT, were attributed to neo-mutation, germinal or somatic mosaicism events. The only SLC6A8-deficient female patient in our series presented with the severe phenotype usually characterizing affected male patients, an observation in agreement with recent evidence that is in support of the fact that this X-linked disorder might be more frequent than expected in the female population with intellectual disability.
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Affiliation(s)
- David Cheillan
- Hospices Civils de Lyon, Service Maladies Héréditaires du Métabolisme et Dépistage Néonatal, Groupement Hospitalier Est, Bron, 69677, France
| | - Marie Joncquel-Chevalier Curt
- Département de Biochimie et Biologie Moléculaire, Laboratoire d’Hormonologie, Métabolisme-Nutrition & Oncologie (HMNO)–Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, Lille, 59037, France
| | - Gilbert Briand
- Département de Biochimie et Biologie Moléculaire, Laboratoire d’Hormonologie, Métabolisme-Nutrition & Oncologie (HMNO)–Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, Lille, 59037, France
- Mass Spectrometry Application Laboratory, University of Lille 2, Lille, 59045, France
| | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center Amsterdam, Amsterdam, The Netherlands
| | - Karine Mention-Mulliez
- Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Jeanne de Flandres, CHRU Lille, Lille, 59037, France
| | - Dries Dobbelaere
- Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Jeanne de Flandres, CHRU Lille, Lille, 59037, France
| | - Jean-Marie Cuisset
- Service de Neurologie Infantile, Hôpital Roger Salengro, CHRU Lille, Lille, 59037, France
| | - Laurence Lion-François
- Service de neurologie pédiatrique, CHU de Lyon-GH Est - Hôpital Femme Mère Enfant, Bron Cedex, 69677, France
| | - Vincent Des Portes
- Service de neurologie pédiatrique, CHU de Lyon-GH Est - Hôpital Femme Mère Enfant, Bron Cedex, 69677, France
| | - Allel Chabli
- Laboratory of Biochemistry, Necker – Enfants Malades Hospital and Université Paris Descartes, Paris, 75015, France
| | - Vassili Valayannopoulos
- Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Necker des Enfants Malades and Université Paris Descartes, 149 rue de Sèvres, Paris, 75015, France
| | - Jean-François Benoist
- Département de Biochimie-Hormonologie, CHU Hôpital Robert Debré, Paris, 75019, France
| | - Jean-Marc Pinard
- Unité de Neurologie Pédiatrique, Département de Pédiatrie, Hôpital Raymond Poincare, Paris-IdF-Ouest University, Paris, France
| | - Gilles Simard
- Laboratoire de Biochimie et Biologie Moléculaire, CHU Angers, Angers, 49033, France
| | - Olivier Douay
- Laboratoire de Biochimie et Biologie Moléculaire, CHU Angers, Angers, 49033, France
| | - Kumaran Deiva
- Service de Neuropédiatrie - CHU de Bicêtre, Le Kremlin Bicêtre Cedex, 94275, France
| | - Alexandra Afenjar
- Service de Neuropédiatrie, Hôpital Armand Trousseau, Groupement hospitalier universitaire Est, Paris, 75012, France
| | - Delphine Héron
- Unité Fonctionnelle de Génétique Médicale AP-HP, Département de Génétique et Cytogénétique, Centre de Référence «Déficiences intellectuelles de causes rares », CRicm, UMR-S975, Groupe Hospitalier Pitié-Salpêtrière, Paris, F-75013, France
| | - François Rivier
- Neuropédiatrie, CHRU Montpellier, & Inserm U1046, Université Montpellier 1 & 2, Montpellier Cedex 5, 34295, France
| | - Brigitte Chabrol
- Service Neuropédiatrie, AP-HM Hôpital de la Timone, Marseille Cedex 5, 13385, France
| | - Fabienne Prieur
- Service de Génétique, CHU de Saint-Étienne Hôpital Nord, Saint-Etienne Cédex 2, 42055, France
| | - François Cartault
- Service de génétique Centre hospitalier Felix Guyon (Saint-Denis) Bellepierre, Saint-Denis cedex, 97405, France
| | - Gaëlle Pitelet
- Service de Neuropédiatrie, Hôpital de l’Archet 2, Nice Cedex 3, 06202, France
| | - Alice Goldenberg
- Service de Génétique Médicale, CHU Ch. Nicolle, Rouen Cedex, 76031, France
| | - Soumeya Bekri
- Institut de Biologie Clinique, CHU Ch. Nicolle, Rouen Cedex, 76031, France
| | - Marion Gerard
- Service de Génétique, CHU Clémenceau, Caen, 14033, France
| | - Richard Delorme
- Service de Pédopsychiatrie CHU Hôpital Robert Debré, Paris, 75019, France
| | - Marc Tardieu
- Service de Neuropédiatrie - CHU de Bicêtre, Le Kremlin Bicêtre Cedex, 94275, France
| | - Nicole Porchet
- Département de Biochimie et Biologie Moléculaire, Laboratoire d’Hormonologie, Métabolisme-Nutrition & Oncologie (HMNO)–Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, Lille, 59037, France
| | - Christine Vianey-Saban
- Hospices Civils de Lyon, Service Maladies Héréditaires du Métabolisme et Dépistage Néonatal, Groupement Hospitalier Est, Bron, 69677, France
| | - Joseph Vamecq
- Département de Biochimie et Biologie Moléculaire, Laboratoire d’Hormonologie, Métabolisme-Nutrition & Oncologie (HMNO)–Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, Lille, 59037, France
- Inserm, Laboratoire Externe, Département du Prof. Nicole Porchet, HMNO, Centre de Biologie et Pathologie (CBP) Pierre-Marie Degand, CHRU Lille, Lille, 59037, France
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Leuzzi V, Mastrangelo M, Battini R, Cioni G. Inborn errors of creatine metabolism and epilepsy. Epilepsia 2012; 54:217-27. [DOI: 10.1111/epi.12020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Mercimek-Mahmutoglu S, Dunbar M, Friesen A, Garret S, Hartnett C, Huh L, Sinclair G, Stockler S, Wellington S, Pouwels PJW, Salomons GS, Jakobs C. Evaluation of two year treatment outcome and limited impact of arginine restriction in a patient with GAMT deficiency. Mol Genet Metab 2012; 105:155-8. [PMID: 22019491 DOI: 10.1016/j.ymgme.2011.09.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 09/30/2011] [Accepted: 09/30/2011] [Indexed: 01/10/2023]
Abstract
A 4-year-old female with history of developmental regression and autistic features was diagnosed with guanidinoacetate methyltransferase deficiency at age 21 months. Upon treatment, she showed improvements in her developmental milestones, sensorial-neural hearing loss and brain atrophy on cranial-MRI. The creatine/choline ratio increased 82% in basal ganglia and 88% in white matter on cranial MR-spectroscopy. The CSF guanidinoacetate decreased 80% after six months of ornithine and creatine supplementation and an additional 8% after 18 months of additional arginine restricted diet. We report the most favorable clinical and biochemical outcome on treatment in our patient.
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Affiliation(s)
- Saadet Mercimek-Mahmutoglu
- Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
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24
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Boggio EM, Lonetti G, Pizzorusso T, Giustetto M. Synaptic determinants of rett syndrome. Front Synaptic Neurosci 2010; 2:28. [PMID: 21423514 PMCID: PMC3059682 DOI: 10.3389/fnsyn.2010.00028] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 06/16/2010] [Indexed: 01/09/2023] Open
Abstract
There is mounting evidence showing that the structural and molecular organization of synaptic connections is affected both in human patients and in animal models of neurological and psychiatric diseases. As a consequence of these experimental observations, it has been introduced the concept of synapsopathies, a notion describing brain disorders of synaptic function and plasticity. A close correlation between neurological diseases and synaptic abnormalities is especially relevant for those syndromes including also mental retardation in their symptomatology, such as Rett syndrome (RS). RS (MIM312750) is an X-linked dominant neurological disorder that is caused in the majority of cases by mutations in methyl-CpG-binding protein 2 (MeCP2). This review will focus on the current knowledge of the synaptic alterations produced by mutations of the gene MeCP2 in mouse models of RS and will highlight prospects experimental therapies currently in use. Different experimental approaches have revealed that RS could be the consequence of an impairment in the homeostasis of synaptic transmission in specific brain regions. Indeed, several forms of experience-induced neuronal plasticity are impaired in the absence of MeCP2. Based on the results presented in this review, it is reasonable to propose that understanding how the brain is affected by diseases such as RS is at reach. This effort will bring us closer to identify the neurobiological bases of human cognition.
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25
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Nasrallah F, Feki M, Kaabachi N. Creatine and creatine deficiency syndromes: biochemical and clinical aspects. Pediatr Neurol 2010; 42:163-71. [PMID: 20159424 DOI: 10.1016/j.pediatrneurol.2009.07.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 06/10/2009] [Accepted: 07/30/2009] [Indexed: 11/28/2022]
Abstract
Creatine deficiency syndromes, which have only recently been described, represent a group of inborn errors of creatine synthesis (L-arginine-glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency) and transport (creatine transporter deficiency). Patients with creatine deficiency syndromes present with mental retardation expressive speech and language delay, and epilepsy. Patients with guanidinoacetate methyltransferase deficiency or creatine transporter deficiency may exhibit autistic behavior. The common denominator of these disorders is the depletion of the brain creatine pool, as demonstrated by in vivo proton magnetic resonance spectroscopy. For diagnosis, laboratory investigations start with analysis of guanidinoacetate, creatine, and creatinine in plasma and urine. Based on these findings, enzyme assays or DNA mutation analysis may be performed. The creatine deficiency syndromes are underdiagnosed, so the possibility should be considered in all children affected by unexplained mental retardation, seizures, and speech delay. Guanidinoacetate methyltransferase deficiency and arginine-glycine amidinotransferase deficiency are treatable by oral creatine supplementation, but patients with creatine transporter deficiency do not respond to this type of treatment.
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26
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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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Deficiencia cerebral de creatina: primeros pacientes españoles con mutaciones en el gen GAMT. Med Clin (Barc) 2009; 133:745-9. [DOI: 10.1016/j.medcli.2009.06.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 06/25/2009] [Indexed: 11/24/2022]
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28
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Inherited metabolic diseases in neurodevelopmental and neurobehavioral disorders. Semin Pediatr Neurol 2008; 15:127-31. [PMID: 18708003 DOI: 10.1016/j.spen.2008.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the past few years, there has been a veritable explosion in the discovery of "new" inborn errors of metabolism. These new conditions are involved in complex pathways of intermediary metabolism affecting processes heretofore unknown. The phenotypes of these new conditions are in many ways milder than the classically described metabolic disorders. Several of these conditions present as nonsyndromic neurodevelopmental and/or neurobehavioral disorders. As such, these conditions should be considered in the differential diagnosis of conditions such as mental retardation, autism spectrum disorders, movement disorders, and cerebral palsy. This article reviews several of these recently described conditions including the clinical presentation, the biochemical profile, the diagnostic approach, and therapeutic options.
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29
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Chahrour M, Jung SY, Shaw C, Zhou X, Wong STC, Qin J, Zoghbi HY. MeCP2, a key contributor to neurological disease, activates and represses transcription. Science 2008; 320:1224-9. [PMID: 18511691 PMCID: PMC2443785 DOI: 10.1126/science.1153252] [Citation(s) in RCA: 1308] [Impact Index Per Article: 81.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mutations in the gene encoding the transcriptional repressor methyl-CpG binding protein 2 (MeCP2) cause the neurodevelopmental disorder Rett syndrome. Loss of function as well as increased dosage of the MECP2 gene cause a host of neuropsychiatric disorders. To explore the molecular mechanism(s) underlying these disorders, we examined gene expression patterns in the hypothalamus of mice that either lack or overexpress MeCP2. In both models, MeCP2 dysfunction induced changes in the expression levels of thousands of genes, but unexpectedly the majority of genes (approximately 85%) appeared to be activated by MeCP2. We selected six genes and confirmed that MeCP2 binds to their promoters. Furthermore, we showed that MeCP2 associates with the transcriptional activator CREB1 at the promoter of an activated target but not a repressed target. These studies suggest that MeCP2 regulates the expression of a wide range of genes in the hypothalamus and that it can function as both an activator and a repressor of transcription.
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Affiliation(s)
- Maria Chahrour
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030 USA
| | - Sung Yun Jung
- Center for Molecular Discovery, Departments of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030 USA
| | - Chad Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030 USA
| | - Xiaobo Zhou
- Center for Bioinformatics, The Methodist Hospital Research Institute and Weill Cornell College of Medicine, Houston, Texas 77030 USA
| | - Stephen T. C. Wong
- Center for Bioinformatics, The Methodist Hospital Research Institute and Weill Cornell College of Medicine, Houston, Texas 77030 USA
| | - Jun Qin
- Center for Molecular Discovery, Departments of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030 USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030 USA
| | - Huda Y. Zoghbi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030 USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030 USA
- Departments of Pediatrics and Neurology, Baylor College of Medicine, Houston, Texas 77030 USA
- Programs in Cell and Molecular Biology and Developmental Biology, Baylor College of Medicine, Houston, Texas 77030 USA
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030 USA
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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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Affiliation(s)
- O Braissant
- Inborn Errors of Metabolism, Clinical Chemistry Laboratory, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
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31
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Sedel F, Gourfinkel-An I, Lyon-Caen O, Baulac M, Saudubray JM, Navarro V. Epilepsy and inborn errors of metabolism in adults: a diagnostic approach. J Inherit Metab Dis 2007; 30:846-54. [PMID: 17957491 DOI: 10.1007/s10545-007-0723-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 09/18/2007] [Accepted: 09/19/2007] [Indexed: 11/24/2022]
Abstract
Inborn errors of metabolism (IEMs) represent poorly known causes of epilepsy in adulthood. Although rare, these are important to recognize for several reasons: some IEMs respond to specific treatments, some antiepileptic drugs interfering with metabolic pathways may worsen the clinical condition, and specific genetic counselling can be provided. We review IEMs potentially revealed by epilepsy that can be encountered in an adult neurology department. We distinguished progressive myoclonic epilepsies (observed in some lysosomal storage diseases, respiratory chain disorders and Lafora disease), from other forms of epilepsies (observed in disorders of intermediary metabolism, including porphyrias, creatine metabolism defects, glucose transporter (GLUT-1) deficiency, Wilson disease or succinic semialdehyde dehydrogenase deficiency). We propose a diagnostic approach and point out clinical, radiological and electrophysiological features that suggest an IEM in an epileptic patient.
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Affiliation(s)
- F Sedel
- Federation of Nervous System Diseases, Reference Center for Lysosomal Diseases, The Salpêtrière Hospital, Pierre et Marie Curie University, Paris, France.
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32
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Mochel F, Barritault J, Boldieu N, Eugène M, Sedel F, Durr A, Seguin F. Apports de la spectroscopie par résonance magnétique nucléaire des fluides dans l’étude de maladies métaboliques et neurodégénératives. Rev Neurol (Paris) 2007; 163:960-5. [DOI: 10.1016/s0035-3787(07)92640-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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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Affiliation(s)
- Krijn T Verbruggen
- University Medical Center Groningen, Beatrix Children's Hospital, University of Groningen, Groningen, The Netherlands.
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34
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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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Affiliation(s)
- Krijn T Verbruggen
- Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, The Netherlands.
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35
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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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Affiliation(s)
- L S Almeida
- Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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