1
|
Goodspeed K, Armstrong D, Dolce A, Evans P, Said R, Tsai P, Sirsi D. Electroencephalographic (EEG) Biomarkers in Genetic Neurodevelopmental Disorders. J Child Neurol 2023; 38:466-477. [PMID: 37264615 PMCID: PMC10644693 DOI: 10.1177/08830738231177386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/17/2022] [Accepted: 04/28/2023] [Indexed: 06/03/2023]
Abstract
Collectively, neurodevelopmental disorders are highly prevalent, but more than a third of neurodevelopmental disorders have an identifiable genetic etiology, each of which is individually rare. The genes associated with neurodevelopmental disorders are often involved in early brain development, neuronal signaling, or synaptic plasticity. Novel treatments for many genetic neurodevelopmental disorders are being developed, but disease-relevant clinical outcome assessments and biomarkers are limited. Electroencephalography (EEG) is a promising noninvasive potential biomarker of brain function. It has been used extensively in epileptic disorders, but its application in neurodevelopmental disorders needs further investigation. In this review, we explore the use of EEG in 3 of the most prevalent genetic neurodevelopmental disorders-Angelman syndrome, Rett syndrome, and fragile X syndrome. Quantitative analyses of EEGs, such as power spectral analysis or measures of connectivity, can quantify EEG signatures seen on qualitative review and potentially correlate with phenotypes. In both Angelman syndrome and Rett syndrome, increased delta power on spectral analysis has correlated with clinical markers of disease severity including developmental disability and seizure burden, whereas spectral power analysis on EEG in fragile X syndrome tends to demonstrate abnormalities in gamma power. Further studies are needed to establish reliable relationships between quantitative EEG biomarkers and clinical phenotypes in rare genetic neurodevelopmental disorders.
Collapse
Affiliation(s)
- Kimberly Goodspeed
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Dallas Armstrong
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alison Dolce
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Patricia Evans
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rana Said
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Peter Tsai
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Deepa Sirsi
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
2
|
Lu G, Zhang Y, Xia H, He X, Xu P, Wu L, Li D, Ma L, Wu J, Peng Q. Identification of a de novo mutation of the FOXG1 gene and comprehensive analysis for molecular factors in Chinese FOXG1-related encephalopathies. Front Mol Neurosci 2022; 15:1039990. [PMID: 36568277 PMCID: PMC9768341 DOI: 10.3389/fnmol.2022.1039990] [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: 09/08/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
Background FOXG1-related encephalopathy, also known as FOXG1 syndrome or FOXG1-related disorder, affects most aspects of development and causes microcephaly and brain malformations. This syndrome was previously considered to be the congenital variant of Rett syndrome. The abnormal function or expression of FOXG1, caused by intragenic mutations, microdeletions or microduplications, was considered to be crucial pathological factor for this disorder. Currently, most of the FOXG1-related encephalopathies have been identified in Europeans and North Americans, and relatively few Chinese cases were reported. Methods Array-Comparative Genomic Hybridization (Array-CGH) and whole-exome sequencing (WES) were carried out for the proband and her parent to detect pathogenic variants. Results A de novo nonsense mutation (c.385G>T, p.Glu129Ter) of FOXG1 was identified in a female child in a cohort of 73 Chinese children with neurodevelopmental disorders/intellectual disorders (NDDs/IDs). In order to have a comprehensive view of FOXG1-related encephalopathy in China, relevant published reports were browsed and twelve cases with mutations in FOXG1 or copy number variants (CNVs) involving FOXG1 gene were involved in the analysis eventually. Feeding difficulties, seizures, delayed speech, corpus callosum hypoplasia and underdevelopment of frontal and temporal lobes occurred in almost all cases. Out of the 12 cases, eight patients (66.67%) had single-nucleotide mutations of FOXG1 gene and four patients (33.33%) had CNVs involving FOXG1 (3 microdeletions and 1 microduplication). The expression of FOXG1 could also be potentially disturbed by deletions of several brain-active regulatory elements located in intergenic FOXG1-PRKD1 region. Further analysis indicated that PRKD1 might be a cooperating factor to regulate the expression of FOXG1, MECP2 and CDKL5 to contribute the RTT/RTT-like disorders. Discussion This re-analysis would broaden the existed knowledge about the molecular etiology and be helpful for diagnosis, treatment, and gene therapy of FOXG1-related disorders in the future.
Collapse
Affiliation(s)
- Guanting Lu
- Laboratory of Translational Medicine Research, Department of Pathology, Deyang People's Hospital, Deyang, China
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Yan Zhang
- Department of Obstetrics and Gynecology, Strategic Support Force Medical Center, Beijing, China
| | - Huiyun Xia
- Department of Child Healthcare, Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen, China
| | - Xiaoyan He
- Laboratory of Translational Medicine Research, Department of Pathology, Deyang People's Hospital, Deyang, China
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Pei Xu
- Laboratory of Translational Medicine Research, Department of Pathology, Deyang People's Hospital, Deyang, China
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Lianying Wu
- Laboratory of Translational Medicine Research, Department of Pathology, Deyang People's Hospital, Deyang, China
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Ding Li
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Liya Ma
- Department of Child Healthcare, Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen, China
| | - Jin Wu
- Laboratory of Translational Medicine Research, Department of Pathology, Deyang People's Hospital, Deyang, China
- Key Laboratory of Tumor Molecular Research of Deyang, Deyang, China
| | - Qiongling Peng
- Department of Child Healthcare, Shenzhen Baoan Women's and Children's Hospital, Jinan University, Shenzhen, China
| |
Collapse
|
3
|
Shovlin S, Delepine C, Swanson L, Bach S, Sahin M, Sur M, Kaufmann WE, Tropea D. Molecular Signatures of Response to Mecasermin in Children With Rett Syndrome. Front Neurosci 2022; 16:868008. [PMID: 35712450 PMCID: PMC9197456 DOI: 10.3389/fnins.2022.868008] [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: 02/01/2022] [Accepted: 04/26/2022] [Indexed: 11/21/2022] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder without effective treatments. Attempts at developing targetted therapies have been relatively unsuccessful, at least in part, because the genotypical and phenotypical variability of the disorder. Therefore, identification of biomarkers of response and patients' stratification are high priorities. Administration of Insulin-like Growth Factor 1 (IGF-1) and related compounds leads to significant reversal of RTT-like symptoms in preclinical mouse models. However, improvements in corresponding clinical trials have not been consistent. A 20-weeks phase I open label trial of mecasermin (recombinant human IGF-1) in children with RTT demonstrated significant improvements in breathing phenotypes. However, a subsequent randomised controlled phase II trial did not show significant improvements in primary outcomes although two secondary clinical endpoints showed positive changes. To identify molecular biomarkers of response and surrogate endpoints, we used RNA sequencing to measure differential gene expression in whole blood samples of participants in the abovementioned phase I mecasermin trial. When all participants (n = 9) were analysed, gene expression was unchanged during the study (baseline vs. end of treatment, T0-T3). However, when participants were subclassified in terms of breathing phenotype improvement, specifically by their plethysmography-based apnoea index, individuals with moderate-severe apnoea and breathing improvement (Responder group) displayed significantly different transcript profiles compared to the other participants in the study (Mecasermin Study Reference group, MSR). Many of the differentially expressed genes are involved in the regulation of cell cycle processes and immune responses, as well as in IGF-1 signalling and breathing regulation. While the Responder group showed limited gene expression changes in response to mecasermin, the MSR group displayed marked differences in the expression of genes associated with inflammatory processes (e.g., neutrophil activation, complement activation) throughout the trial. Our analyses revealed gene expression profiles associated with severe breathing phenotype and its improvement after mecasermin administration in RTT, and suggest that inflammatory/immune pathways and IGF-1 signalling contribute to treatment response. Overall, these data support the notion that transcript profiles have potential as biomarkers of response to IGF-1 and related compounds.
Collapse
Affiliation(s)
- Stephen Shovlin
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Chloe Delepine
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Lindsay Swanson
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Snow Bach
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States.,Department of Neurology, Boston Children's Hospital, Boston, MA, United States
| | - Daniela Tropea
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland.,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland
| |
Collapse
|
4
|
Role of DNA Methyl-CpG-Binding Protein MeCP2 in Rett Syndrome Pathobiology and Mechanism of Disease. Biomolecules 2021; 11:biom11010075. [PMID: 33429932 PMCID: PMC7827577 DOI: 10.3390/biom11010075] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 12/16/2022] Open
Abstract
Rett Syndrome (RTT) is a severe, rare, and progressive developmental disorder with patients displaying neurological regression and autism spectrum features. The affected individuals are primarily young females, and more than 95% of patients carry de novo mutation(s) in the Methyl-CpG-Binding Protein 2 (MECP2) gene. While the majority of RTT patients have MECP2 mutations (classical RTT), a small fraction of the patients (atypical RTT) may carry genetic mutations in other genes such as the cyclin-dependent kinase-like 5 (CDKL5) and FOXG1. Due to the neurological basis of RTT symptoms, MeCP2 function was originally studied in nerve cells (neurons). However, later research highlighted its importance in other cell types of the brain including glia. In this regard, scientists benefitted from modeling the disease using many different cellular systems and transgenic mice with loss- or gain-of-function mutations. Additionally, limited research in human postmortem brain tissues provided invaluable findings in RTT pathobiology and disease mechanism. MeCP2 expression in the brain is tightly regulated, and its altered expression leads to abnormal brain function, implicating MeCP2 in some cases of autism spectrum disorders. In certain disease conditions, MeCP2 homeostasis control is impaired, the regulation of which in rodents involves a regulatory microRNA (miR132) and brain-derived neurotrophic factor (BDNF). Here, we will provide an overview of recent advances in understanding the underlying mechanism of disease in RTT and the associated genetic mutations in the MECP2 gene along with the pathobiology of the disease, the role of the two most studied protein variants (MeCP2E1 and MeCP2E2 isoforms), and the regulatory mechanisms that control MeCP2 homeostasis network in the brain, including BDNF and miR132.
Collapse
|