1
|
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.
Collapse
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
| |
Collapse
|
2
|
Pickrell WO, Fry AE. Epilepsy genetics: a practical guide for adult neurologists. Pract Neurol 2023; 23:111-119. [PMID: 36639246 DOI: 10.1136/pn-2022-003623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2022] [Indexed: 01/15/2023]
Abstract
An understanding of epilepsy genetics is important for adult neurologists, as making a genetic diagnosis gives clinical benefit. In this review, we describe the key features of different groups of genetic epilepsies. We describe the common available genetic tests for epilepsy, and how to interpret them.
Collapse
Affiliation(s)
- William Owen Pickrell
- Department of Neurology, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Andrew E Fry
- All Wales Medical Genomics Service, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Balestrini S, Guerrini R, Sisodiya SM. Rare and Complex Epilepsies from Childhood to Adulthood: Requirements for Separate Management or Scope for a Lifespan Holistic Approach? Curr Neurol Neurosci Rep 2021; 21:65. [PMID: 34817708 PMCID: PMC8613076 DOI: 10.1007/s11910-021-01154-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE In this descriptive review, we describe current models of transition in rare and complex epilepsy syndromes and propose alternative approaches for more holistic management based on disease biology. RECENT FINDINGS Previously published guidance and recommendations on transition strategies in individuals with epilepsy have not been systematically and uniformly applied. There is significant heterogeneity in models of transition/transfer of care across countries and even within the same country. We provide examples of the most severe epilepsy and related syndromes and emphasise the limited data on their outcome in adulthood. Rare and complex epilepsy syndromes have unique presentations and require high levels of expertise and multidisciplinary approach. Lifespan clinics, with no transition, but instead continuity of care from childhood to adulthood with highly specialised input from healthcare providers, may represent an alternative effective approach. Effectiveness should be measured by evaluation of quality of life for both patients and their families/caregivers.
Collapse
Affiliation(s)
- Simona Balestrini
- Department of Clinical and Experimental Epilepsy, University College of London (UCL) Queen Square Institute of Neurology, London WC1N 3BG and Chalfont Centre for Epilepsy, London, Bucks, UK.
- Neuroscience Department, Meyer Children's Hospital, European Reference Network ERN EpiCARE, 50139, Florence, Italy.
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children's Hospital, European Reference Network ERN EpiCARE, 50139, Florence, Italy
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, University College of London (UCL) Queen Square Institute of Neurology, London WC1N 3BG and Chalfont Centre for Epilepsy, London, Bucks, UK
| |
Collapse
|
5
|
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.
Collapse
|
6
|
Sisodiya SM. Precision medicine and therapies of the future. Epilepsia 2020; 62 Suppl 2:S90-S105. [PMID: 32776321 PMCID: PMC8432144 DOI: 10.1111/epi.16539] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/24/2022]
Abstract
Precision medicine in the epilepsies has gathered much attention, especially with gene discovery pushing forward new understanding of disease biology. Several targeted treatments are emerging, some with considerable sophistication and individual‐level tailoring. There have been rare achievements in improving short‐term outcomes in a few very select patients with epilepsy. The prospects for further targeted, repurposed, or novel treatments seem promising. Along with much‐needed success, difficulties are also arising. Precision treatments do not always work, and sometimes are inaccessible or do not yet exist. Failures of precision medicine may not find their way to broader scrutiny. Precision medicine is not a new concept: It has been boosted by genetics and is often focused on genetically determined epilepsies, typically considered to be driven in an individual by a single genetic variant. Often the mechanisms generating the full clinical phenotype from such a perceived single cause are incompletely understood. The impact of additional genetic variation and other factors that might influence the clinical presentation represent complexities that are not usually considered. Precision success and precision failure are usually equally incompletely explained. There is a need for more comprehensive evaluation and a more rigorous framework, bringing together information that is both necessary and sufficient to explain clinical presentation and clinical responses to precision treatment in a precision approach that considers the full picture not only of the effects of a single variant, but also of its genomic and other measurable environment, within the context of the whole person. As we may be on the brink of a treatment revolution, progress must be considered and reasoned: One possible framework is proposed for the evaluation of precision treatments.
Collapse
Affiliation(s)
- Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Bucks, UK
| |
Collapse
|
7
|
Rostami P, Hosseinpour S, Ashrafi MR, Alizadeh H, Garshasbi M, Tavasoli AR. Primary creatine deficiency syndrome as a potential missed diagnosis in children with psychomotor delay and seizure: case presentation with two novel variants and literature review. Acta Neurol Belg 2020; 120:511-516. [PMID: 31222513 DOI: 10.1007/s13760-019-01168-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 06/06/2019] [Indexed: 11/24/2022]
Abstract
Creatine is the main source of energy for the brain. Primary creatine deficiency syndromes (PCDSs) are inborn error of metabolism of creatine synthesis. Symptoms of central nervous system involvement are the most common clinical manifestations in these disorders. We reviewed medical records of all genetically confirmed patients diagnosed by whole exome sequencing who were referred to Myelin and Neurodegenerative Disorders Clinic, Children's Medical Center, Tehran, Iran, from May 2016 to Dec 2018. A literature review was conducted on clinical and genomic variability of PCDS to compare our patients with previously reported cases. We report two patients with creatine deficiency among a cohort of 550 registered cases out of which 200 patients had a genetically confirmed neurodegenerative disorder diagnosis. The main complain in the first patient with creatine transporter (CRTR) deficiency was seizure and genetic study in this patient identified a novel hemizygote variant of "c.92 > T; p.Pro31Leu" in the first exon of SLC6A8 gene. The second patient with guanidinoacetate methyltransferase (GAMT) deficiency had an unknown motor and speech delay as the striking manifestation and molecular assay revealed a novel homozygote variant of "c.134G > A; p.Trp45*" in the first exon of GAMT gene. PCDSs usually are associated with nonspecific neurologic symptoms. The first presented case had a mean delayed diagnosis of 5 years. Therefore, in children with unexplained neurologic features including developmental delay and/or regression, mental disability and repeated seizures without any significant findings in metabolic studies, PCDSs can be considered as a differential diagnosis and molecular analysis can be helpful for the precise diagnosis and treatment.
Collapse
Affiliation(s)
- Parastoo Rostami
- Division of Pediatric Endocrinology and Metabolism, Growth and Development Research Center, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Sareh Hosseinpour
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Houman Alizadeh
- Division of Pediatric Radiology, Department of Pediatrics, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran.
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic (Iranian Neurometabolic Registry), Pediatric Neurology Division, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
8
|
Marques EP, Ferreira FS, Santos TM, Prezzi CA, Martins LAM, Bobermin LD, Quincozes-Santos A, Wyse ATS. Cross-talk between guanidinoacetate neurotoxicity, memory and possible neuroprotective role of creatine. Biochim Biophys Acta Mol Basis Dis 2019; 1865:165529. [PMID: 31398469 DOI: 10.1016/j.bbadis.2019.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/21/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022]
Abstract
Guanidinoacetate Methyltransferase deficiency is an inborn error of metabolism that results in decreased creatine and increased guanidinoacetate (GAA) levels. Patients present neurological symptoms whose mechanisms are unclear. We investigated the effects of an intrastriatal administration of 10 μM of GAA (0.02 nmol/striatum) on energy metabolism, redox state, inflammation, glutamate homeostasis, and activities/immunocontents of acetylcholinesterase and Na+,K+-ATPase, as well as on memory acquisition. The neuroprotective role of creatine was also investigated. Male Wistar rats were pretreated with creatine (50 mg/kg) or saline for 7 days underwenting stereotactic surgery. Forty-eight hours after surgery, the animals (then sixty-days-old) were divided into groups: Control, GAA, GAA + Creatine, and Creatine. Experiments were performed 30 min after intrastriatal infusion. GAA decreased SDH, complexes II and IV activities, and ATP levels, but had no effect on mitochondrial mass/membrane potential. Creatine totally prevented SDH and complex II, and partially prevented COX and ATP alterations. GAA increased dichlorofluorescein levels and decreased superoxide dismutase and catalase activities. Creatine only prevented catalase and dichlorofluorescein alterations. GAA increased cytokines, nitrites levels and acetylcholinesterase activity, but not its immunocontent. Creatine prevented such effects, except nitrite levels. GAA decreased glutamate uptake, but had no effect on the immunocontent of its transporters. GAA decreased Na+,K+-ATPase activity and increased the immunocontent of its α3 subunit. The performance on the novel object recognition task was also impaired. Creatine partially prevented the changes in glutamate uptake and Na+,K+-ATPase activity, and completely prevented the memory impairment. This study helps to elucidate the protective effects of creatine against the damage caused by GAA.
Collapse
Affiliation(s)
- Eduardo Peil Marques
- Laboratory of Neuroprotection and Neurometabolic Diseases, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil; Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Fernanda Silva Ferreira
- Laboratory of Neuroprotection and Neurometabolic Diseases, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil; Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Tiago Marcon Santos
- Laboratory of Neuroprotection and Neurometabolic Diseases, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil; Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Caroline Acauan Prezzi
- Laboratory of Neuroprotection and Neurometabolic Diseases, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil; Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Leo A M Martins
- Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Larissa Daniele Bobermin
- Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil
| | - Angela T S Wyse
- Laboratory of Neuroprotection and Neurometabolic Diseases, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil; Program of Post-graduation in Biological Sciences-Biochemistry, Biochemistry Department, ICBS, Universidade Federal do Rio Grande do Sul, Street Ramiro Barcelos, 2600-Annex, CEP 90035-003 Porto Alegre, RS, Brazil.
| |
Collapse
|
9
|
Juneja M, Azmi A, Baets J, Roos A, Jennings MJ, Saveri P, Pisciotta C, Bernard-Marissal N, Schneider BL, Verfaillie C, Chrast R, Seeman P, Hahn AF, de Jonghe P, Maudsley S, Horvath R, Pareyson D, Timmerman V. PFN2 and GAMT as common molecular determinants of axonal Charcot-Marie-Tooth disease. J Neurol Neurosurg Psychiatry 2018; 89:870-878. [PMID: 29449460 DOI: 10.1136/jnnp-2017-317562] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/24/2018] [Accepted: 01/30/2018] [Indexed: 11/04/2022]
Abstract
BACKGROUND Charcot-Marie-Tooth type 2 (CMT2) neuropathy is characterised by a vast clinical and genetic heterogeneity complicating its diagnosis and therapeutic intervention. Identification of molecular signatures that are common to multiple CMT2 subtypes can aid in developing therapeutic strategies and measuring disease outcomes. METHODS A proteomics-based approach was performed on lymphoblasts from CMT2 patients genetically diagnosed with different gene mutations to identify differentially regulated proteins. The candidate proteins were validated through real-time quantitative PCR and western blotting on lymphoblast samples of patients and controls, motor neurons differentiated from patient-derived induced pluripotent stem cells (iPSCs) and sciatic nerves of CMT2 mouse models. RESULTS Proteomic profiling of patient lymphoblasts resulted in the identification of profilin 2 (PFN2) and guanidinoacetate methyltransferase (GAMT) as commonly downregulated proteins in different genotypes compared with healthy controls. This decrease was also observed at the transcriptional level on screening 43 CMT2 patients and 22 controls, respectively. A progressive decrease in PFN2 expression with age was observed in patients, while in healthy controls its expression increased with age. Reduced PFN2 expression was also observed in motor neurons differentiated from CMT2 patient-derived iPSCs and sciatic nerves of CMT2 mice when compared with controls. However, no change in GAMT levels was observed in motor neurons and CMT2 mouse-derived sciatic nerves. CONCLUSIONS We unveil PFN2 and GAMT as molecular determinants of CMT2 with possible indications of the role of PFN2 in the pathogenesis and disease progression. This is the first study describing biomarkers that can boost the development of therapeutic strategies targeting a wider spectrum of CMT2 patients.
Collapse
Affiliation(s)
- Manisha Juneja
- Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium.,Institute Born Bunge, Antwerp, Belgium
| | - Abdelkrim Azmi
- VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Jonathan Baets
- Institute Born Bunge, Antwerp, Belgium.,VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Andreas Roos
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Matthew J Jennings
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Paola Saveri
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Chiara Pisciotta
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Nathalie Bernard-Marissal
- Aix Marseille University, INSERM, MMG, U1251, Marseille, France.,Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bernard L Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - Roman Chrast
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pavel Seeman
- DNA Laboratory, Department of Child Neurology, 2nd Medical School, Charles University and University Hospital Motol, Prague, Czech Republic
| | - Angelika F Hahn
- Department of Clinical Neurological Sciences Centre, University Hospital, Western University, London, Ontario, Canada
| | - Peter de Jonghe
- Institute Born Bunge, Antwerp, Belgium.,VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Rita Horvath
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Davide Pareyson
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium.,Institute Born Bunge, Antwerp, Belgium
| |
Collapse
|