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Alyazidi AS, Muthaffar OY, Shawli MK, Ahmed RA, Aljefri YF, Baaishrah LS, Jambi AT, Alotibi FA. Phenotypic and Molecular Spectrum of Guanidinoacetate N-Methyltransferase Deficiency: An Analytical Study of a Case Series and a Scoping Review of 53 Cases of Guanidinoacetate N-Methyltransferase. J Microsc Ultrastruct 2024; 12:81-90. [PMID: 39006040 PMCID: PMC11245129 DOI: 10.4103/jmau.jmau_16_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/24/2022] [Accepted: 06/02/2022] [Indexed: 12/02/2022] Open
Abstract
Background Guanidinoacetate methyltransferase deficiency (GAMT) is an autosomal recessive inborn error of metabolism. A condition that results from a pathogenic variant in the GAMT gene that maps to 19p13.3. The prevalence can be estimated to be up to 1:2,640,000 cases; countries such as Saudi Arabia could have a higher prevalence due to high consanguinity rates. The clinical manifestations that a patient could obtain are broad and start to manifest in the patients' early childhood years. Materials and Methods A thorough review of case reports in January 2022 was conducted. The retrieved literature was screened for demographic data. Patients of all ages were included. Qualitative variables were described as number and percentage (%), and quantitative data were described by the mean and standard deviation. In bivariate data, Chi-square test (χ2) was used and t-test for nonparametric variables. Results Gender distribution was 53% of males and 47% females. Reported age ranged from 8 to 31 months. At the age of onset, 50% of the cases were infants, 28% were toddlers, and 15% were children, concluding that 79% of the reported cases developed symptoms before 5 years old. 68% of the cases developed generalized seizures throughout their life. 84% of the cases expressed a form of developmental delay. 43% of the cases had intellectual disabilities and mental retardation that affected their learning process; most cases required special care. 23% of the affected cases were of consanguineous marriages, and 7% had affected relatives. Conclusion We described four novel case reports, the first to be reported in Saudi Arabia. Seizure was a leading finding in the majority of the cases. Developmental delay was broadly observed. Intellectual delay and language impairments are primary hallmarks. Further understanding and early diagnosis are recommended. Premarital testing of neurogenetic diseases using whole-exome sequencing is probably a future direction, especially in populations with high consanguinity rates.
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Affiliation(s)
- Anas S. Alyazidi
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Osama Y. Muthaffar
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammed K. Shawli
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Renad A. Ahmed
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Yara Fahad Aljefri
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Layan Saleh Baaishrah
- Undergraduate Student, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Abdulaziz T. Jambi
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Fahad A. Alotibi
- Undergraduate Student, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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Khoja S, Lambert J, Nitzahn M, Eliav A, Zhang Y, Tamboline M, Le CT, Nasser E, Li Y, Patel P, Zhuravka I, Lueptow LM, Tkachyova I, Xu S, Nissim I, Schulze A, Lipshutz GS. Gene therapy for guanidinoacetate methyltransferase deficiency restores cerebral and myocardial creatine while resolving behavioral abnormalities. Mol Ther Methods Clin Dev 2022; 25:278-296. [PMID: 35505663 PMCID: PMC9051621 DOI: 10.1016/j.omtm.2022.03.015] [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: 11/29/2021] [Accepted: 03/27/2022] [Indexed: 11/06/2022]
Abstract
Creatine deficiency disorders are inborn errors of creatine metabolism, an energy homeostasis molecule. One of these, guanidinoacetate N-methyltransferase (GAMT) deficiency, has clinical characteristics that include features of autism, self-mutilation, intellectual disability, and seizures, with approximately 40% having a disorder of movement; failure to thrive can also be a component. Along with low creatine levels, guanidinoacetic acid (GAA) toxicity has been implicated in the pathophysiology of the disorder. Present-day therapy with oral creatine to control GAA lacks efficacy; seizures can persist. Dietary management and pharmacological ornithine treatment are challenging. Using an AAV-based gene therapy approach to express human codon-optimized GAMT in hepatocytes, in situ hybridization, and immunostaining, we demonstrated pan-hepatic GAMT expression. Serial collection of blood demonstrated a marked early and sustained reduction of GAA with normalization of plasma creatine; urinary GAA levels also markedly declined. The terminal time point demonstrated marked improvement in cerebral and myocardial creatine levels. In conjunction with the biochemical findings, treated mice gained weight to nearly match their wild-type littermates, while behavioral studies demonstrated resolution of abnormalities; PET-CT imaging demonstrated improvement in brain metabolism. In conclusion, a gene therapy approach can result in long-term normalization of GAA with increased creatine in guanidinoacetate N-methyltransferase deficiency and at the same time resolves the behavioral phenotype in a murine model of the disorder. These findings have important implications for the development of a new therapy for this abnormality of creatine metabolism.
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Affiliation(s)
- Suhail Khoja
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - Jenna Lambert
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - Matthew Nitzahn
- Molecular Biology Institute, UCLA, Los Angeles, CA 90025, USA
| | - Adam Eliav
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - YuChen Zhang
- Semel Institute for Neuroscience, UCLA, Los Angeles, CA 90025, USA
| | - Mikayla Tamboline
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA 90025, USA.,Departments of Molecular and Medical Pharmacology, Universtiy of California, Los Angeles, CA 90025, USA
| | - Colleen T Le
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - Eram Nasser
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - Yunfeng Li
- Departments of Pathology and Laboratory Medicine, UCLA, Los Angeles, CA 90025, USA
| | - Puja Patel
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA
| | - Irina Zhuravka
- Behavioral Testing Core, Department of Psychology, UCLA, Los Angeles, CA 90025, USA
| | - Lindsay M Lueptow
- Behavioral Testing Core, Department of Psychology, UCLA, Los Angeles, CA 90025, USA
| | - Ilona Tkachyova
- Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Shili Xu
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA 90025, USA.,Departments of Molecular and Medical Pharmacology, Universtiy of California, Los Angeles, CA 90025, USA.,Jonsson Comprehensive Cancer Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA
| | - Itzhak Nissim
- Division of Metabolism and Human Genetics, Children's Hospital of Philadelphia, and the Department of Biochemistry and Biophysics, Perlman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andreas Schulze
- Department of Paediatrics, University of Toronto, Toronto, ON M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON M5G 1X8, Canada.,Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Gerald S Lipshutz
- Department of Surgery, UCLA, Los Angeles, CA 90025, USA.,Molecular Biology Institute, UCLA, Los Angeles, CA 90025, USA.,Semel Institute for Neuroscience, UCLA, Los Angeles, CA 90025, USA.,Departments of Molecular and Medical Pharmacology, Universtiy of California, Los Angeles, CA 90025, USA.,Intellectual and Developmental Disabilities Research Center, UCLA, Los Angeles, CA 90025, USA
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Intellectual Disability and Brain Creatine Deficit: Phenotyping of the Genetic Mouse Model for GAMT Deficiency. Genes (Basel) 2021; 12:genes12081201. [PMID: 34440375 PMCID: PMC8391262 DOI: 10.3390/genes12081201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 11/17/2022] Open
Abstract
Guanidinoacetate methyltransferase deficiency (GAMT-D) is one of three cerebral creatine (Cr) deficiency syndromes due to pathogenic variants in the GAMT gene (19p13.3). GAMT-D is characterized by the accumulation of guanidinoacetic acid (GAA) and the depletion of Cr, which result in severe global developmental delay (and intellectual disability), movement disorder, and epilepsy. The GAMT knockout (KO) mouse model presents biochemical alterations in bodily fluids, the brain, and muscles, including increased GAA and decreased Cr and creatinine (Crn) levels, which are similar to those observed in humans. At the behavioral level, only limited and mild alterations have been reported, with a large part of analyzed behaviors being unaffected in GAMT KO as compared with wild-type mice. At the cerebral level, decreased Cr and Crn and increased GAA and other guanidine compound levels have been observed. Nevertheless, the effects of Cr deficiency and GAA accumulation on many neurochemical, morphological, and molecular processes have not yet been explored. In this review, we summarize data regarding behavioral and cerebral GAMT KO phenotypes, and focus on uncharted behavioral alterations that are comparable with the clinical symptoms reported in GAMT-D patients, including intellectual disability, poor speech, and autistic-like behaviors, as well as unexplored Cr-induced cerebral alterations.
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