1
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Aida N. 1H-MR Spectroscopy of the Early Developmental Brain, Neonatal Encephalopathies, and Neurometabolic Disorders. Magn Reson Med Sci 2021; 21:9-28. [PMID: 34421092 PMCID: PMC9199977 DOI: 10.2463/mrms.rev.2021-0055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
MRI interpretations of the pediatric brain are often challenging for general radiologists and clinicians because MR signals and morphology are continuously changing in the developing brain. Furthermore, the developing brain reacts differently to injuries, resulting in imaging characteristics that differ from those of the mature brain. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive method for assessing neurological abnormalities at the microscopic level and measures in vivo brain metabolites using a clinical MR machine. In MR examinations of the pediatric brain, 1H-MRS demonstrates its powerful diagnostic capability when MRI is insufficient for diagnostic features. MRI and 1H-MRS may be complementary tools for diagnosing and monitoring diseases. However, there is currently no consensus on how to include 1H-MRS in clinical MR examinations. An overview of the clinical implementation of 1H-MRS for the assessment of early pediatric developmental brains as well as the diagnosis, prognostification, and disease monitoring of various non-neoplastic brain disorders, including neonatal encephalopathies and neurometabolic/neurodegenerative diseases, was provided herein. Qualitative and quantitative 1H-MRS is a powerful non-invasive tool for accessing various brain metabolites to confirm age appropriate peaks and detect abnormal peaks or deficient or reduced peaks, which may facilitate the identification of metabolic and neurodegenerative disorders as well as damage associated with hypoxic-ischemic encephalopathy (HIE). Moreover, 1H-MRS has potential as a biomarker for monitoring therapeutic efficacy in metabolic diseases and neonatal HIE. It also provides insights into the pathophysiologies of various disorders, which may facilitate the use of novel therapeutic approaches. Therefore, 1H-MRS needs to be included more frequently in routine clinical MR examinations of pediatric patients with neurological disorders.
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Affiliation(s)
- Noriko Aida
- Department of Radiology, Kanagawa Children's Medical Center.,Department of Diagnostic Radiology, Yokohama City University Graduate School of Medicine
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Cameron JM, Levandovskiy V, Roberts W, Anagnostou E, Scherer S, Loh A, Schulze A. Variability of Creatine Metabolism Genes in Children with Autism Spectrum Disorder. Int J Mol Sci 2017; 18:ijms18081665. [PMID: 28758966 PMCID: PMC5578055 DOI: 10.3390/ijms18081665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/19/2017] [Accepted: 07/25/2017] [Indexed: 12/23/2022] Open
Abstract
Creatine deficiency syndrome (CDS) comprises three separate enzyme deficiencies with overlapping clinical presentations: arginine:glycine amidinotransferase (GATM gene, glycine amidinotransferase), guanidinoacetate methyltransferase (GAMT gene), and creatine transporter deficiency (SLC6A8 gene, solute carrier family 6 member 8). CDS presents with developmental delays/regression, intellectual disability, speech and language impairment, autistic behaviour, epileptic seizures, treatment-refractory epilepsy, and extrapyramidal movement disorders; symptoms that are also evident in children with autism. The objective of the study was to test the hypothesis that genetic variability in creatine metabolism genes is associated with autism. We sequenced GATM, GAMT and SLC6A8 genes in 166 patients with autism (coding sequence, introns and adjacent untranslated regions). A total of 29, 16 and 25 variants were identified in each gene, respectively. Four variants were novel in GATM, and 5 in SLC6A8 (not present in the 1000 Genomes, Exome Sequencing Project (ESP) or Exome Aggregation Consortium (ExAC) databases). A single variant in each gene was identified as non-synonymous, and computationally predicted to be potentially damaging. Nine variants in GATM were shown to have a lower minor allele frequency (MAF) in the autism population than in the 1000 Genomes database, specifically in the East Asian population (Fisher’s exact test). Two variants also had lower MAFs in the European population. In summary, there were no apparent associations of variants in GAMT and SLC6A8 genes with autism. The data implying there could be a lower association of some specific GATM gene variants with autism is an observation that would need to be corroborated in a larger group of autism patients, and with sub-populations of Asian ethnicities. Overall, our findings suggest that the genetic variability of creatine synthesis/transport is unlikely to play a part in the pathogenesis of autism spectrum disorder (ASD) in children.
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Affiliation(s)
- Jessie M Cameron
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, ON M5G 0A4, Canada.
| | - Valeriy Levandovskiy
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, ON M5G 0A4, Canada.
| | - Wendy Roberts
- Department of Paediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada.
- Holland Bloorview Kids Rehabilitation Hospital, 150 Kigour Rd, Toronto, ON M4G 1R8, Canada.
| | - Evdokia Anagnostou
- Department of Paediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada.
- Holland Bloorview Kids Rehabilitation Hospital, 150 Kigour Rd, Toronto, ON M4G 1R8, Canada.
| | - Stephen Scherer
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, ON M5G 0A4, Canada.
- The Centre for Applied Genomics and Genetics and Genome Biology, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
- McLaughlin Centre and Department of Molecular Genetics, 686 Bay Street, 13th Floor, Peter Gilgan Center for Research and Learning, Toronto, ON M5G 0A4, Canada.
| | - Alvin Loh
- Department of Paediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada.
- Surrey Place Center, 2 Surrey Place, Toronto, ON M5S 2C2, Canada.
| | - Andreas Schulze
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, ON M5G 0A4, Canada.
- Department of Paediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
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3
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Uemura T, Ito S, Ohta Y, Tachikawa M, Wada T, Terasaki T, Ohtsuki S. Abnormal N-Glycosylation of a Novel Missense Creatine Transporter Mutant, G561R, Associated with Cerebral Creatine Deficiency Syndromes Alters Transporter Activity and Localization. Biol Pharm Bull 2017; 40:49-55. [PMID: 28049948 DOI: 10.1248/bpb.b16-00582] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebral creatine deficiency syndromes (CCDSs) are caused by loss-of-function mutations in creatine transporter (CRT, SLC6A8), which transports creatine at the blood-brain barrier and into neurons of the central nervous system (CNS). This results in low cerebral creatine levels, and patients exhibit mental retardation, poor language skills and epilepsy. We identified a novel human CRT gene missense mutation (c.1681 G>C, G561R) in Japanese CCDSs patients. The purpose of the present study was to evaluate the reduction of creatine transport in G561R-mutant CRT-expressing 293 cells, and to clarify the mechanism of its functional attenuation. G561R-mutant CRT exhibited greatly reduced creatine transport activity compared to wild-type CRT (WT-CRT) when expressed in 293 cells. Also, the mutant protein is localized mainly in intracellular membrane fraction, while WT-CRT is localized in plasma membrane. Western blot analysis revealed a 68 kDa band of WT-CRT protein in plasma membrane fraction, while G561R-mutant CRT protein predominantly showed bands at 55, 110 and 165 kDa in crude membrane fraction. The bands of both WT-CRT and G561R-mutant CRT were shifted to 50 kDa by N-glycosidase treatment. Our results suggest that the functional impairment of G561R-mutant CRT was probably caused by incomplete N-linked glycosylation due to misfolding during protein maturation, leading to oligomer formation and changes of cellular localization.
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Affiliation(s)
- Tatsuki Uemura
- Department of Pharmaceutical Microbiology, Graduate School of Pharmaceutical Sciences, Kumamoto University
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Schulze A, Bauman M, Tsai ACH, Reynolds A, Roberts W, Anagnostou E, Cameron J, Nozzolillo AA, Chen S, Kyriakopoulou L, Scherer SW, Loh A. Prevalence of Creatine Deficiency Syndromes in Children With Nonsyndromic Autism. Pediatrics 2016; 137:peds.2015-2672. [PMID: 26684475 DOI: 10.1542/peds.2015-2672] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/12/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Creatine deficiency may play a role in the neurobiology of autism and may represent a treatable cause of autism. The goal of the study was to ascertain the prevalence of creatine deficiency syndromes (CDSs) in children with autism spectrum disorder (ASD). METHODS In a prospective multicenter study, 443 children were investigated after a confirmed diagnosis of ASD. Random spot urine screening for creatine metabolites (creatine, guanidinoacetate, creatinine, and arginine) with liquid chromatography-tandem mass spectrometry and second-tier testing with high-performance liquid chromatography methodology was followed by recall testing in 24-hour urines and confirmatory testing by Sanger-based DNA sequencing of GAMT, GATM, and SLC6A8 genes. Additional diagnostic tests included plasma creatine metabolites and in vivo brain proton magnetic resonance spectroscopy. The creatine metabolites in spot urine in the autism group were compared with 128 healthy controls controlled for age. RESULTS In 443 subjects with ASD investigated for CDS, we had 0 events (event: 0, 95% confidence interval 0-0.0068), therefore with 95% confidence the prevalence of CDS is <7 in 1000 children with ASD. The autism and control groups did not vary in terms of creatine metabolites (P > .0125) in urine. CONCLUSION Our study revealed a very low prevalence of CDS in children with nonsyndromic ASD and no obvious association between creatine metabolites and autism. Unlike our study population, we expect more frequent CDS among children with severe developmental delay, speech impairment, seizures, and movement disorders in addition to impairments in social communication, restricted interests, and repetitive behaviors.
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Affiliation(s)
- Andreas Schulze
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada; Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Paediatrics, University of Toronto, Ontario, Canada;
| | - Margaret Bauman
- Lurie Center for Autism, MassGeneral Hospital, Boston, Massachusetts; Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts
| | - Anne Chun-Hui Tsai
- Colorado University Medical School, Aurora, Colorado; Molecular and Medical Genetics, Oregon Health and Sciences University, Portland, Oregon
| | - Ann Reynolds
- Colorado University Medical School, Aurora, Colorado
| | - Wendy Roberts
- Department of Paediatrics, University of Toronto, Ontario, Canada; Holland Bloorview Kids Rehabilitation, Toronto, Ontario, Canada
| | - Evdokia Anagnostou
- Department of Paediatrics, University of Toronto, Ontario, Canada; Holland Bloorview Kids Rehabilitation, Toronto, Ontario, Canada
| | - Jessie Cameron
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada
| | - Alixandra A Nozzolillo
- Clinical and Translational Science Center, Harvard Medical School, Boston, Massachusetts
| | - Shiyi Chen
- Clinical Research Services, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Lianna Kyriakopoulou
- Department of Paediatric Laboratory Medicine, Biochemical Genetics Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephen W Scherer
- Genetics and Genome Biology, Peter Gilgan Center for Research and Learning, Toronto, Ontario, Canada; The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Ontario, Canada
| | - Alvin Loh
- Department of Paediatrics, University of Toronto, Ontario, Canada; Surrey Place Center, Toronto, Ontario, Canada
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5
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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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6
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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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7
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Xu X, Xu Q, Zhang Y, Zhang X, Cheng T, Wu B, Ding Y, Lu P, Zheng J, Zhang M, Qiu Z, Yu X. A case report of Chinese brothers with inherited MECP2-containing duplication: autism and intellectual disability, but not seizures or respiratory infections. BMC MEDICAL GENETICS 2012; 13:75. [PMID: 22909152 PMCID: PMC3506511 DOI: 10.1186/1471-2350-13-75] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/15/2012] [Indexed: 11/16/2022]
Abstract
Background Autistic spectrum disorders (ASDs) are a family of neurodevelopmental disorders with strong genetic components. Recent studies have shown that copy number variations in dosage sensitive genes can contribute significantly to these disorders. One such gene is the transcription factor MECP2, whose loss of function in females results in Rett syndrome, while its duplication in males results in developmental delay and autism. Case presentation Here, we identified a Chinese family with two brothers both inheriting a 2.2 Mb MECP2-containing duplication (151,369,305 – 153,589,577) from their mother. In addition, both brothers also had a 213.7 kb duplication on Chromosome 2, inherited from their father. The older brother also carried a 48.4 kb duplication on Chromosome 2 inherited from the mother, and a 8.2 kb deletion at 11q13.5 inherited from the father. Based on the published literature, MECP2 is the most autism-associated gene among the identified CNVs. Consistently, the boys displayed clinical features in common with other patients carrying MECP2 duplications, including intellectual disability, autism, lack of speech, slight hypotonia and unsteadiness of movement. They also had slight dysmorphic features including a depressed nose bridge, large ears and midface hypoplasia. Interestingly, they did not exhibit other clinical features commonly observed in American-European patients with MECP2 duplication, including recurrent respiratory infections and epilepsy. Conclusions To our knowledge, this is the first identification and characterization of Chinese Han patients with MECP2-containing duplications. Further cases are required to determine if the above described clinical differences are due to individual variations or related to the genetic background of the patients.
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Affiliation(s)
- Xiu Xu
- Department of Child Healthcare, Children's Hospital of Fudan University, Shanghai, China.
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8
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Kurosawa Y, DeGrauw TJ, Lindquist DM, Blanco VM, Pyne-Geithman GJ, Daikoku T, Chambers JB, Benoit SC, Clark JF. Cyclocreatine treatment improves cognition in mice with creatine transporter deficiency. J Clin Invest 2012; 122:2837-46. [PMID: 22751104 PMCID: PMC3408730 DOI: 10.1172/jci59373] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/23/2012] [Indexed: 01/06/2023] Open
Abstract
The second-largest cause of X-linked mental retardation is a deficiency in creatine transporter (CRT; encoded by SLC6A8), which leads to speech and language disorders with severe cognitive impairment. This syndrome, caused by the absence of creatine in the brain, is currently untreatable because CRT is required for creatine entry into brain cells. Here, we developed a brain-specific Slc6a8 knockout mouse (Slc6a8-/y) as an animal model of human CRT deficiency in order to explore potential therapies for this syndrome. The phenotype of the Slc6a8-/y mouse was comparable to that of human patients. We successfully treated the Slc6a8-/y mice with the creatine analog cyclocreatine. Brain cyclocreatine and cyclocreatine phosphate were detected after 9 weeks of cyclocreatine treatment in Slc6a8-/y mice, in contrast to the same mice treated with creatine or placebo. Cyclocreatine-treated Slc6a8-/y mice also exhibited a profound improvement in cognitive abilities, as seen with novel object recognition as well as spatial learning and memory tests. Thus, cyclocreatine appears promising as a potential therapy for CRT deficiency.
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Affiliation(s)
- Yuko Kurosawa
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ton J. DeGrauw
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Diana M. Lindquist
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Victor M. Blanco
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Gail J. Pyne-Geithman
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Takiko Daikoku
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - James B. Chambers
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Stephen C. Benoit
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joseph F. Clark
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Neurology and
Department of Radiology and Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Emergency Medicine and
Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, USA.
Division of Reproductive Science, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Psychiatry and Behavior Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
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9
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Gurrieri F. Working up autism: The practical role of medical genetics. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:104-10. [DOI: 10.1002/ajmg.c.31326] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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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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11
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Abstract
Autism is an etiologically and clinically heterogeneous group of disorders, diagnosed solely by the complex behavioral phenotype. On the basis of the high-heritability index, geneticists are confident that autism will be the first behavioral disorder for which the genetic basis can be well established. Although it was initially assumed that major genome-wide and candidate gene association studies would lead most directly to common autism genes, progress has been slow. Rather, most discoveries have come from studies of known genetic disorders associated with the behavioral phenotype. New technology, especially array chromosomal genomic hybridization, has both increased the identification of putative autism genes and raised to approximately 25%, the percentage of children for whom an autism-related genetic change can be identified. Incorporating clinical geneticists into the diagnostic and autism research arenas is vital to the field. Interpreting this new technology and deciphering autism's genetic montage require the skill set of the clinical geneticist including knowing how to acquire and interpret family pedigrees, how to analyze complex morphologic, neurologic, and medical phenotypes, sorting out heterogeneity, developing rational genetic models, and designing studies. The current emphasis on deciphering autism spectrum disorders has accelerated the field of neuroscience and demonstrated the necessity of multidisciplinary research that must include clinical geneticists both in the clinics and in the design and implementation of basic, clinical, and translational research.
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12
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Alcaide P, Rodriguez-Pombo P, Ruiz-Sala P, Ferrer I, Castro P, Ruiz Martin Y, Merinero B, Ugarte M. A new case of creatine transporter deficiency associated with mild clinical phenotype and a novel mutation in the SLC6A8 gene. Dev Med Child Neurol 2010; 52:215-7. [PMID: 20002129 DOI: 10.1111/j.1469-8749.2009.03480.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Benvenuto A, Moavero R, Alessandrelli R, Manzi B, Curatolo P. Syndromic autism: causes and pathogenetic pathways. World J Pediatr 2009; 5:169-76. [PMID: 19693459 DOI: 10.1007/s12519-009-0033-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 03/18/2009] [Indexed: 12/16/2022]
Abstract
BACKGROUND Autism is a severe neurodevelopmental disorder known to have many different etiologies. In the last few years, significant progresses have been made in comprehending the causes of autism and their multiple impacts on the developing brain. This article aims to review the current understanding of the etiologies and the multiple pathogenetic pathways that are likely to lead to the autistic phenotype. DATA SOURCES The PubMed database was searched with the keywords "autism" and "chromosomal abnormalities", "metabolic diseases", "susceptibility loci". RESULTS Genetic syndromes, defined mutations, and metabolic diseases account for less than 20% of autistic patients. Alterations of the neocortical excitatory/inhibitory balance and perturbations of interneurons' development represent the most probable pathogenetic mechanisms underlying the autistic phenotype in fragile X syndrome and tuberous sclerosis complex. Chromosomal abnormalities and potential candidate genes are strongly implicated in the disruption of neural connections, brain growth and synaptic/dendritic morphology. Metabolic and mitochondrial defects may have toxic effects on the brain cells, causing neuronal loss and altered modulation of neurotransmission systems. CONCLUSIONS A wide variety of cytogenetic abnormalities have been recently described, particularly in the low functioning individuals with dysmorphic features. Routine metabolic screening studies should be performed in the presence of autistic regression or suggestive clinical findings. As etiologies of autism are progressively discovered, the number of individuals with idiopathic autism will progressively shrink. Studies of genetic and environmentally modulated epigenetic factors are beginning to provide some clues to clarify the complexities of autism pathogenesis. The role of the neuropediatrician will be to understand the neurological basis of autism, and to identify more homogenous subgroups with specific biologic markers.
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Affiliation(s)
- Arianna Benvenuto
- Department of Neuroscience, Pediatric Neurology Unit, Tor Vergata University, via Montpellier 1, 00133, Rome, RM, Italy
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