1
|
Brito F, Lagos C, Cubillos J, Orellana J, Gajardo M, Böhme D, Encina G, Repetto GM. Genomic analysis in Chilean patients with suspected Rett syndrome: keep a broad differential diagnosis. Front Genet 2024; 15:1278198. [PMID: 38566815 PMCID: PMC10986174 DOI: 10.3389/fgene.2024.1278198] [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: 08/15/2023] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Introduction: Rett syndrome (RTT, MIM #312750) is a rare genetic disorder that leads to developmental regression and severe disability and is caused by pathogenic variants in the MECP2 gene. The diagnosis of RTT is based on clinical features and, depending on resources and access, on molecular confirmation. There is scarce information on molecular diagnosis from patients in Latin America, mostly due to limited availability and coverage of genomic testing. This pilot study aimed to implement genomic testing and characterize clinical and molecular findings in a group of Chilean patients with a clinical diagnosis of RTT. Methods: Twenty-eight patients with suspected RTT underwent characterization of phenotypic manifestations and molecular testing using Clinical Exome SolutionTM CES_V2 by SOPHiA Genetics. Data was analyzed using the commercial bioinformatics platform, SOPHiA DDMTM. A virtual panel of 34 genes, including MECP2 and other genes that are in the differential diagnosis of RTT, was used to prioritize initial analyses, followed by evaluation of the complete exome sequence data. Results: Twelve patients (42.8% of participants) had variants in MECP2, of which 11 (39.2%) were interpreted as pathogenic/likely pathogenic (P/LP), thus confirming the diagnosis of RTT in them. Eight additional patients (28.5%) harbored ten variants in nine other genes. Four of these variants were interpreted as P/LP (14.2%) (GRIN2B, MADD, TRPM3 and ZEB2) resulting in alternative neurodevelopmental diagnoses, and six were considered of uncertain significance. No evident candidate variant was found for eight patients. Discussion: This study allowed to reach a diagnosis in half of the participants. The diagnosis of RTT was confirmed in over a third of them, while others were found to have alternative neurodevelopmental disorders. Further evaluation is needed to identify the cause in those with negative or uncertain results. This information is useful for the patients, families, and clinicians to guide clinical management, even more so since the development of novel therapies for RTT. We also show the feasibility of implementing a step-wide approach to genomic testing in a setting with limited resources.
Collapse
Affiliation(s)
- Florencia Brito
- Rare Diseases Program, Center for Genetics and Genomics, Institute of Sciences and Innovation in Medicine, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Catalina Lagos
- Rare Diseases Program, Center for Genetics and Genomics, Institute of Sciences and Innovation in Medicine, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | | | - Joan Orellana
- Rare Diseases Program, Center for Genetics and Genomics, Institute of Sciences and Innovation in Medicine, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Mallen Gajardo
- Escuela de Ingeniería, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Daniela Böhme
- Rare Diseases Program, Center for Genetics and Genomics, Institute of Sciences and Innovation in Medicine, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
- Biosoluciones-UDD, Santiago, Chile
| | | | - Gabriela M. Repetto
- Rare Diseases Program, Center for Genetics and Genomics, Institute of Sciences and Innovation in Medicine, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| |
Collapse
|
2
|
Pascual-Alonso A, Xiol C, Smirnov D, Kopajtich R, Prokisch H, Armstrong J. Identification of molecular signatures and pathways involved in Rett syndrome using a multi-omics approach. Hum Genomics 2023; 17:85. [PMID: 37710353 PMCID: PMC10503149 DOI: 10.1186/s40246-023-00532-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 09/03/2023] [Indexed: 09/16/2023] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a neurodevelopmental disorder mainly caused by mutations in the methyl-CpG-binding protein 2 gene (MECP2). MeCP2 is a multi-functional protein involved in many cellular processes, but the mechanisms by which its dysfunction causes disease are not fully understood. The duplication of the MECP2 gene causes a distinct disorder called MECP2 duplication syndrome (MDS), highlighting the importance of tightly regulating its dosage for proper cellular function. Additionally, some patients with mutations in genes other than MECP2 exhibit phenotypic similarities with RTT, indicating that these genes may also play a role in similar cellular functions. The purpose of this study was to characterise the molecular alterations in patients with RTT in order to identify potential biomarkers or therapeutic targets for this disorder. METHODS We used a combination of transcriptomics (RNAseq) and proteomics (TMT mass spectrometry) to characterise the expression patterns in fibroblast cell lines from 22 patients with RTT and detected mutation in MECP2, 15 patients with MDS, 12 patients with RTT-like phenotypes and 13 healthy controls. Transcriptomics and proteomics data were used to identify differentially expressed genes at both RNA and protein levels, which were further inspected via enrichment and upstream regulator analyses and compared to find shared features in patients with RTT. RESULTS We identified molecular alterations in cellular functions and pathways that may contribute to the disease phenotype in patients with RTT, such as deregulated cytoskeletal components, vesicular transport elements, ribosomal subunits and mRNA processing machinery. We also compared RTT expression profiles with those of MDS seeking changes in opposite directions that could lead to the identification of MeCP2 direct targets. Some of the deregulated transcripts and proteins were consistently affected in patients with RTT-like phenotypes, revealing potentially relevant molecular processes in patients with overlapping traits and different genetic aetiology. CONCLUSIONS The integration of data in a multi-omics analysis has helped to interpret the molecular consequences of MECP2 dysfunction, contributing to the characterisation of the molecular landscape in patients with RTT. The comparison with MDS provides knowledge of MeCP2 direct targets, whilst the correlation with RTT-like phenotypes highlights processes potentially contributing to the pathomechanism leading these disorders.
Collapse
Affiliation(s)
- Ainhoa Pascual-Alonso
- Fundació Per La Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Clara Xiol
- Fundació Per La Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Dmitrii Smirnov
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Judith Armstrong
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain.
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III (ISCIII), Madrid, Spain.
- Genomic Unit, Molecular and Genetic Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain.
| |
Collapse
|
3
|
Frankel E, Podder A, Sharifi M, Pillai R, Belnap N, Ramsey K, Dodson J, Venugopal P, Brzezinski M, Llaci L, Gerald B, Mills G, Sanchez-Castillo M, Balak CD, Szelinger S, Jepsen WM, Siniard AL, Richholt R, Naymik M, Schrauwen I, Craig DW, Piras IS, Huentelman MJ, Schork NJ, Narayanan V, Rangasamy S. Genetic and Protein Network Underlying the Convergence of Rett-Syndrome-like (RTT-L) Phenotype in Neurodevelopmental Disorders. Cells 2023; 12:1437. [PMID: 37408271 DOI: 10.3390/cells12101437] [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: 02/07/2023] [Revised: 04/20/2023] [Accepted: 04/29/2023] [Indexed: 07/07/2023] Open
Abstract
Mutations of the X-linked gene encoding methyl-CpG-binding protein 2 (MECP2) cause classical forms of Rett syndrome (RTT) in girls. A subset of patients who are recognized to have an overlapping neurological phenotype with RTT but are lacking a mutation in a gene that causes classical or atypical RTT can be described as having a 'Rett-syndrome-like phenotype (RTT-L). Here, we report eight patients from our cohort diagnosed as having RTT-L who carry mutations in genes unrelated to RTT. We annotated the list of genes associated with RTT-L from our patient cohort, considered them in the light of peer-reviewed articles on the genetics of RTT-L, and constructed an integrated protein-protein interaction network (PPIN) consisting of 2871 interactions connecting 2192 neighboring proteins among RTT- and RTT-L-associated genes. Functional enrichment analysis of RTT and RTT-L genes identified a number of intuitive biological processes. We also identified transcription factors (TFs) whose binding sites are common across the set of RTT and RTT-L genes and appear as important regulatory motifs for them. Investigation of the most significant over-represented pathway analysis suggests that HDAC1 and CHD4 likely play a central role in the interactome between RTT and RTT-L genes.
Collapse
Affiliation(s)
- Eric Frankel
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Avijit Podder
- Quantitative Medicine Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Megan Sharifi
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Roshan Pillai
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Newell Belnap
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Julius Dodson
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Pooja Venugopal
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Molly Brzezinski
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Lorida Llaci
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- Quantitative Medicine Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Brittany Gerald
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Gabrielle Mills
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Meredith Sanchez-Castillo
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Chris D Balak
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Szabolcs Szelinger
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Wayne M Jepsen
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Ashley L Siniard
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Ryan Richholt
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Marcus Naymik
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Department of Neurology, Gertrude H. Sergievsky Center, Columbia University Medical Center, New York, NY 10032, USA
| | - David W Craig
- Department of Translational Genomics, University of Southern California, Los Angeles, CA 90033, USA
| | - Ignazio S Piras
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Matthew J Huentelman
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- Quantitative Medicine Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Nicholas J Schork
- Quantitative Medicine Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Vinodh Narayanan
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| | - Sampathkumar Rangasamy
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
- Center for Rare Childhood Disorders (C4RCD), Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA
| |
Collapse
|
4
|
Kessi M, Chen B, Shan LD, Wang Y, Yang L, Yin F, He F, Peng J, Wang G. Genotype-phenotype correlations of STXBP1 pathogenic variants and the treatment choices for STXBP1-related disorders in China. BMC Med Genomics 2023; 16:46. [PMID: 36882827 PMCID: PMC9990233 DOI: 10.1186/s12920-023-01474-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 02/28/2023] [Indexed: 03/09/2023] Open
Abstract
BACKGROUND We aimed to analyze the genotype-phenotype correlations of STXBP1 pathogenic variants, prognostic factors and the treatment choices in a case-series of STXBP1-related disorders from China. METHODS The clinical data and genetic results of the children diagnosed with STXBP1-related disorders at Xiangya hospital from 2011 to 2019 were collected retrospectively, and analyzed. We divided our patients into groups for comparison purposes: patients with missense variants and nonsense variants, patients who are seizure-free and not seizure-free, patients with mild to moderate intellectual disability (ID) and severe to profound global developmental delay (GDD). RESULTS Nineteen patients were enrolled: 17 (89.5%) unrelated and 2 (10.5%) familial. Twelve (63.2%) were females. Developmental epileptic encephalopathy (DEE) was observed in 18 (94.7%) patients and ID alone in 1 (5.3%) individual. Thirteen patients (68.4%) had profound ID/GDD, 4 (23.53%) severe, 1 (5.9%) moderate and 1 (5.9%) mild. Three patients (15.8%) with profound ID died. A total of 19 variants were detected: pathogenic (n = 15) and likely pathogenic (n = 4). Seven were novel variants: c.664-1G>-, M486R, H245N, H498Pfs*44, L41R, L410del, and D90H. Of the 8 previous reported variants, 2 were recurrent: R406C and R292C. Anti-seizure medications were used in combinations, and 7 patients became seizure-free, and most of them achieved seizure freedom within the first 2 years of life irrespective of the type of the mutation. Effective medications for the seizure-free individuals included adrenocorticotropic (ACTH) and/or levetiracetam and/or phenobarbital and/or sodium valproate and/or topiramate and/or vigabatrin and/or nitrazepam. There was no correlation between the types of pathogenic variants and the phenotypes. CONCLUSION Our case-series showed that there is no genotype-phenotype correlation in patients with STXBP1-related disorders. This study adds 7 novel variants which expand the spectrum of STXBP1-related disorders. Combinations of levetiracetam and/or sodium valproate and/or ACTH and/or phenobarbital and/or vigabatrin and/or topiramate and/or nitrazepam were more often associated with seizure freedom in our cohort within 2 years of life.
Collapse
Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Li-Dan Shan
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Ying Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China
| | - Guoli Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China. .,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, Hunan, China.
| |
Collapse
|
5
|
Comprehensive In Silico Functional Prediction Analysis of CDKL5 by Single Amino Acid Substitution in the Catalytic Domain. Int J Mol Sci 2022; 23:ijms232012281. [PMID: 36293137 PMCID: PMC9603577 DOI: 10.3390/ijms232012281] [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: 09/09/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) is a serine/threonine protein kinase whose pathological mutations cause CDKL5 deficiency disorder. Most missense mutations are concentrated in the catalytic domain. Therefore, anticipating whether mutations in this region affect CDKL5 function is informative for clinical diagnosis. This study comprehensively predicted the pathogenicity of all 5700 missense substitutions in the catalytic domain of CDKL5 using in silico analysis and evaluating their accuracy. Each missense substitution was evaluated as “pathogenic” or “benign”. In silico tools PolyPhen-2 HumDiv mode/HumVar mode, PROVEAN, and SIFT were selected individually or in combination with one another to determine their performance using 36 previously reported mutations as a reference. Substitutions predicted as pathogenic were over 88.0% accurate using each of the three tools. The best performance score (accuracy, 97.2%; sensitivity, 100%; specificity, 66.7%; and Matthew’s correlation coefficient (MCC), 0.804) was achieved by combining PolyPhen-2 HumDiv, PolyPhen-2 HumVar, and PROVEAN. This provided comprehensive information that could accurately predict the pathogenicity of the disease, which might be used as an aid for clinical diagnosis.
Collapse
|
6
|
Siqueira E, Obiols-Guardia A, Jorge-Torres OC, Oliveira-Mateos C, Soler M, Ramesh-Kumar D, Setién F, van Rossum D, Pascual-Alonso A, Xiol C, Ivan C, Shimizu M, Armstrong J, Calin GA, Pasterkamp RJ, Esteller M, Guil S. Analysis of the circRNA and T-UCR populations identifies convergent pathways in mouse and human models of Rett syndrome. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:621-644. [PMID: 35036070 PMCID: PMC8749388 DOI: 10.1016/j.omtn.2021.12.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/17/2021] [Indexed: 01/07/2023]
Abstract
Noncoding RNAs play regulatory roles in physiopathology, but their involvement in neurodevelopmental diseases is poorly understood. Rett syndrome is a severe, progressive neurodevelopmental disorder linked to loss-of-function mutations of the MeCP2 gene for which no cure is yet available. Analysis of the noncoding RNA profile corresponding to the brain-abundant circular RNA (circRNA) and transcribed-ultraconserved region (T-UCR) populations in a mouse model of the disease reveals widespread dysregulation and enrichment in glutamatergic excitatory signaling and microtubule cytoskeleton pathways of the corresponding host genes. Proteomic analysis of hippocampal samples from affected individuals confirms abnormal levels of several cytoskeleton-related proteins together with key alterations in neurotransmission. Importantly, the glutamate receptor GRIA3 gene displays altered biogenesis in affected individuals and in vitro human cells and is influenced by expression of two ultraconserved RNAs. We also describe post-transcriptional regulation of SIRT2 by circRNAs, which modulates acetylation and total protein levels of GluR-1. As a consequence, both regulatory mechanisms converge on the biogenesis of AMPA receptors, with an effect on neuronal differentiation. In both cases, the noncoding RNAs antagonize MeCP2-directed regulation. Our findings indicate that noncoding transcripts may contribute to key alterations in Rett syndrome and are not only useful tools for revealing dysregulated processes but also molecules of biomarker value.
Collapse
Affiliation(s)
- Edilene Siqueira
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
- National Council for Scientific and Technological Development (CNPq), Brasilia, 71605-001 Federal District, Brazil
| | - Aida Obiols-Guardia
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
| | - Olga C. Jorge-Torres
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
| | | | - Marta Soler
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Deepthi Ramesh-Kumar
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Fernando Setién
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
| | - Daniëlle van Rossum
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Ainhoa Pascual-Alonso
- Fundación San Juan de Dios, Barcelona, 08950 Catalonia, Spain
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
| | - Clara Xiol
- Fundación San Juan de Dios, Barcelona, 08950 Catalonia, Spain
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
| | - Cristina Ivan
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Masayoshi Shimizu
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Judith Armstrong
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
- Servei de Medicina Genètica i Molecular, Hospital Sant Joan de Déu, Barcelona, 08950 Catalonia, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - George A. Calin
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Center for RNA Interference and Non-coding RNAs, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - R. Jeroen Pasterkamp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Manel Esteller
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Centro de Investigacion Biomedica en Red Cancer (CIBERONC), Madrid, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08010 Catalonia, Spain
- Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), Barcelona, 08907 Catalonia, Spain
| | - Sonia Guil
- Josep Carreras Leukaemia Research Institute (IJC), Badalona, Barcelona, 08916 Catalonia, Spain
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, 08908 Catalonia, Spain
- Germans Trias i Pujol Health Science Research Institute, Badalona, Barcelona, 08916 Catalonia, Spain
| |
Collapse
|
7
|
Technological Improvements in the Genetic Diagnosis of Rett Syndrome Spectrum Disorders. Int J Mol Sci 2021; 22:ijms221910375. [PMID: 34638716 PMCID: PMC8508637 DOI: 10.3390/ijms221910375] [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: 07/30/2021] [Revised: 09/17/2021] [Accepted: 09/22/2021] [Indexed: 11/17/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that constitutes the second most common cause of intellectual disability in females worldwide. In the past few years, the advancements in genetic diagnosis brought by next generation sequencing (NGS), have made it possible to identify more than 90 causative genes for RTT and significantly overlapping phenotypes (RTT spectrum disorders). Therefore, the clinical entity known as RTT is evolving towards a spectrum of overlapping phenotypes with great genetic heterogeneity. Hence, simultaneous multiple gene testing and thorough phenotypic characterization are mandatory to achieve a fast and accurate genetic diagnosis. In this review, we revise the evolution of the diagnostic process of RTT spectrum disorders in the past decades, and we discuss the effectiveness of state-of-the-art genetic testing options, such as clinical exome sequencing and whole exome sequencing. Moreover, we introduce recent technological advancements that will very soon contribute to the increase in diagnostic yield in patients with RTT spectrum disorders. Techniques such as whole genome sequencing, integration of data from several “omics”, and mosaicism assessment will provide the tools for the detection and interpretation of genomic variants that will not only increase the diagnostic yield but also widen knowledge about the pathophysiology of these disorders.
Collapse
|
8
|
Spagnoli C, Fusco C, Pisani F. Rett Syndrome Spectrum in Monogenic Developmental-Epileptic Encephalopathies and Epilepsies: A Review. Genes (Basel) 2021; 12:genes12081157. [PMID: 34440332 PMCID: PMC8394997 DOI: 10.3390/genes12081157] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 01/22/2023] Open
Abstract
INTRODUCTION Progress in the clinical application of next-generation-sequencing-based techniques has resulted in a dramatic increase in the recognized genetic heterogeneity of the Rett syndrome spectrum (RSS). Our awareness of the considerable overlap with pediatric-onset epilepsies and epileptic/developmental encephalopathies (EE/DE) genes is also growing, and the presence of variable clinical features inside a general frame of commonalities has drawn renewed attention into deep phenotyping. METHODS We decided to review the medical literature on atypical Rett syndrome and "Rett-like" phenotypes, with special emphasis on described cases with pediatric-onset epilepsies and/or EE-DE, evaluating Neul's criteria for Rett syndrome and associated movement disorders and notable stereotypies. RESULTS "Rett-like" features were described in syndromic and non-syndromic monogenic epilepsy- and DE/EE-related genes, in "intellectual disability plus epilepsy"-related genes and in neurodegenerative disorders. Additionally, prominent stereotypies can be observed in monogenic complex neurodevelopmental disorders featuring epilepsy with or without autistic features outside of the RSS. CONCLUSIONS Patients share a complex neurodevelopmental and neurological phenotype (developmental delay, movement disorder) with impaired gait, abnormal tone and hand stereotypies. However, the presence and characteristics of regression and loss of language and functional hand use can differ. Finally, the frequency of additional supportive criteria and their distribution also vary widely.
Collapse
Affiliation(s)
- Carlotta Spagnoli
- Child Neurology Unit, AUSL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy;
- Correspondence:
| | - Carlo Fusco
- Child Neurology Unit, AUSL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy;
| | - Francesco Pisani
- Child Neuropsychiatry Unit, University-Hospital of Parma, 43123 Parma, Italy;
| |
Collapse
|
9
|
MECP2-Related Disorders and Epilepsy Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
MECP2 (methyl-CpG binding protein-2) gene, located on chromosome Xq28, encodes for a protein particularly abundant in the brain that is required for maturation of astrocytes and neurons and is developmentally regulated. A defective homeostasis of MECP2 expression, either by haploinsufficiency or overexpression, leads to a neurodevelopmental phenotype. As MECP2 is located on chromosome X, the clinical presentation varies in males and females ranging from mild learning disabilities to severe encephalopathies and early death. Typical Rett syndrome (RTT), the most frequent phenotype associated with MECP2 mutations, primarily affects girls and it was previously thought to be lethal in males; however, MECP2 duplication syndrome, resulting from a duplication of the Xq28 region including MECP2, leads to a severe neurodevelopmental disorder in males. RTT and MECP2 duplication syndrome share overlapping clinical phenotypes including intellectual disabilities, motor deficits, hypotonia, progressive spasticity, and epilepsy. In this manuscript we reviewed literature on epilepsy related to MECP2 disorders, focusing on clinical presentation, genotype–phenotype correlation, and treatment.
Collapse
|
10
|
Henriksen MW, Breck H, Sejersted Y, Diseth T, von Tetzchner S, Paus B, Skjeldal OH. Genetic and clinical variations in a Norwegian sample diagnosed with Rett syndrome. Brain Dev 2020; 42:484-495. [PMID: 32336485 DOI: 10.1016/j.braindev.2020.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND PURPOSE Rett syndrome (RTT) is a neurodevelopmental disorder mainly caused by mutations in MECP2. The diagnostic criteria of RTT are clinical; mutations in MECP2 are neither diagnostic nor necessary, and a mutation in another gene does not exclude RTT. We attempted to correlate genotype and phenotype to see if there are significant clinical associations. METHODS All available females diagnosed with RTT in Norway were invited to the study. Parents were interviewed, the girl or woman with RTT examined and medical records reviewed. All diagnoses were revisited according to the current diagnostic criteria and exome-based sequencing analyses were performed in individuals without an identified causative mutation. Participants were categorized according to genotypes and RTT diagnosis. Individuals with RTT with and without mutations in MECP2 were compared. RESULTS Ninety-one individuals were included. A presumed causative mutation was identified in 86 individuals, of these, mutations in MECP2 in 77 individuals and mutations in SMC1A, SYNGAP1, SCN1A, CDKL5, FOXG1 or chromosome 13q in nine. Seventy-two individuals fulfilled the diagnostic criteria for classic and 12 for atypical RTT. Significant differences in early development, loss of hand use and language, intense eye gaze and the presence of early onset epilepsy were revealed in individuals with RTT according to their MECP2 genotypic status. CONCLUSION Using the current diagnostic criteria, genetic and clinical variation in RTT is considerable. Significant differences between individuals with RTT with and without MECP2 mutations indicate that MECP2 is a major determinant for the clinical phenotype in individuals with RTT.
Collapse
Affiliation(s)
- Mari Wold Henriksen
- Department of Neurology, Drammen Hospital, Vestre Viken Hospital Trust, P.O. Box 800, 3004 Drammen, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, P.O. Box 1171, Blindern 0318, Oslo, Norway.
| | - Hilde Breck
- Department of Habilitation, Innlandet Hospital Trust, Anders Sandvigs v. 17, 2629 Lillehammer, Norway; Department of Psychology, University of Oslo, P.O. Box 1094, Blindern 0317, Oslo, Norway
| | - Yngve Sejersted
- Department of Medical Genetics, Oslo University Hospital, Box 4950, 0424 Oslo, Norway
| | - Trond Diseth
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, P.O. Box 1171, Blindern 0318, Oslo, Norway
| | - Stephen von Tetzchner
- Department of Psychology, University of Oslo, P.O. Box 1094, Blindern 0317, Oslo, Norway
| | - Benedicte Paus
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, P.O. Box 1171, Blindern 0318, Oslo, Norway; Department of Medical Genetics, Oslo University Hospital, Box 4950, 0424 Oslo, Norway
| | - Ola H Skjeldal
- Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Kungsgatan 12, 41119 Gothenburg, Sweden
| |
Collapse
|
11
|
D'haene E, Bar-Yaacov R, Bariah I, Vantomme L, Van Loo S, Cobos FA, Verboom K, Eshel R, Alatawna R, Menten B, Birnbaum RY, Vergult S. A neuronal enhancer network upstream of MEF2C is compromised in patients with Rett-like characteristics. Hum Mol Genet 2020; 28:818-827. [PMID: 30445463 PMCID: PMC6381311 DOI: 10.1093/hmg/ddy393] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/01/2018] [Accepted: 11/08/2018] [Indexed: 01/06/2023] Open
Abstract
Mutations in myocyte enhancer factor 2C (MEF2C), an important transcription factor in neurodevelopment, are associated with a Rett-like syndrome. Structural variants (SVs) upstream of MEF2C, which do not disrupt the gene itself, have also been found in patients with a similar phenotype, suggesting that disruption of MEF2C regulatory elements can also cause a Rett-like phenotype. To characterize those elements that regulate MEF2C during neural development and that are affected by these SVs, we used genomic tools coupled with both in vitro and in vivo functional assays. Through circularized chromosome conformation capture sequencing
(4C-seq) and the assay for transposase-accessible chromatin using sequencing
(ATAC-seq), we revealed a complex interaction network in which the MEF2C promoter physically contacts several distal enhancers that are deleted or translocated by disease-associated SVs. A total of 16 selected candidate regulatory sequences were tested for enhancer activity in vitro, with 14 found to be functional enhancers. Further analyses of their in vivo activity in zebrafish showed that each of these enhancers has a distinct activity pattern during development, with eight enhancers displaying neuronal activity. In summary, our results disentangle a complex regulatory network governing neuronal MEF2C expression that involves multiple distal enhancers. In addition, the characterized neuronal enhancers pose as novel candidates to screen for mutations in neurodevelopmental disorders, such as Rett-like syndrome.
Collapse
Affiliation(s)
- Eva D'haene
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium
| | - Reut Bar-Yaacov
- Department of Life Sciences, Faculty of Natural Sciences, The Ben-Gurion University of the Negev, Beersheba, Israel.,Center of Evolutionary Genomics and Medicine, The Ben-Gurion University of the Negev, Beersheba, Israel
| | - Inbar Bariah
- Department of Life Sciences, Faculty of Natural Sciences, The Ben-Gurion University of the Negev, Beersheba, Israel.,Center of Evolutionary Genomics and Medicine, The Ben-Gurion University of the Negev, Beersheba, Israel
| | - Lies Vantomme
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium
| | - Sien Van Loo
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium
| | - Francisco Avila Cobos
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), 9000 Ghent, Belgium.,Bioinformatics Institute Ghent from Nucleotides to Networks (BIG N2N), Ghent, Belgium
| | - Karen Verboom
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), 9000 Ghent, Belgium
| | - Reut Eshel
- Department of Life Sciences, Faculty of Natural Sciences, The Ben-Gurion University of the Negev, Beersheba, Israel.,Center of Evolutionary Genomics and Medicine, The Ben-Gurion University of the Negev, Beersheba, Israel
| | - Rawan Alatawna
- Department of Life Sciences, Faculty of Natural Sciences, The Ben-Gurion University of the Negev, Beersheba, Israel.,Center of Evolutionary Genomics and Medicine, The Ben-Gurion University of the Negev, Beersheba, Israel
| | - Björn Menten
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium
| | - Ramon Y Birnbaum
- Department of Life Sciences, Faculty of Natural Sciences, The Ben-Gurion University of the Negev, Beersheba, Israel.,Center of Evolutionary Genomics and Medicine, The Ben-Gurion University of the Negev, Beersheba, Israel
| | - Sarah Vergult
- Center for Medical Genetics, Ghent University, 9000 Ghent, Belgium
| |
Collapse
|
12
|
Wang J, Zhang Q, Chen Y, Yu S, Wu X, Bao X. Rett and Rett-like syndrome: Expanding the genetic spectrum to KIF1A and GRIN1 gene. Mol Genet Genomic Med 2019; 7:e968. [PMID: 31512412 PMCID: PMC6825848 DOI: 10.1002/mgg3.968] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/03/2019] [Accepted: 08/09/2019] [Indexed: 12/19/2022] Open
Abstract
Background This study aimed to investigate the new genetic etiologies of Rett syndrome (RTT) or Rett‐like phenotypes. Methods Targeted next‐generation sequencing (NGS) was performed on 44 Chinese patients with RTT or Rett‐like phenotypes, in whom genetic analysis of MECP2, CDKL5, and FOXG1 was negative. Results The detection rate was 31.8% (14/44). A de novo pathogenic variant (c.275_276ins AA, p. Cys92*) of KIF1A was identified in a girl with all core features of typical RTT. A patient with atypical RTT was detected having de novo GRIN1 pathogenic variant (c.2337C > A, p. Val793Phe). Additionally, compound heterozygous pathogenic variants of PPT1 gene were detected in a girl, who initially displayed typical RTT features, but progressed into neuronal ceroid lipofuscinoses (NCL) afterwards. Pathogenic variants in KCNQ2, MEF2C, WDR45, TCF4, IQSEC2, and SDHA were also found in our cohort. Conclusions It is the first time that pathogenic variants of GRIN1 and KIF1A were linked to RTT and Rett‐like profiles. Our findings expanded the genetic heterogeneity of Chinese RTT or Rett‐like patients, and also suggest that some patients with genetic metabolic disease such as NCL, might displayed Rett features initially, and clinical follow‐up is essential for the diagnosis.
Collapse
Affiliation(s)
- Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Shujie Yu
- Department of Neurology, Harbin Children's Hospital, Harbin, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| |
Collapse
|
13
|
FOXG1-Related Syndrome: From Clinical to Molecular Genetics and Pathogenic Mechanisms. Int J Mol Sci 2019; 20:ijms20174176. [PMID: 31454984 PMCID: PMC6747066 DOI: 10.3390/ijms20174176] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 08/25/2019] [Indexed: 12/29/2022] Open
Abstract
Individuals with mutations in forkhead box G1 (FOXG1) belong to a distinct clinical entity, termed “FOXG1-related encephalopathy”. There are two clinical phenotypes/syndromes identified in FOXG1-related encephalopathy, duplications and deletions/intragenic mutations. In children with deletions or intragenic mutations of FOXG1, the recognized clinical features include microcephaly, developmental delay, severe cognitive disabilities, early-onset dyskinesia and hyperkinetic movements, stereotypies, epilepsy, and cerebral malformation. In contrast, children with duplications of FOXG1 are typically normocephalic and have normal brain magnetic resonance imaging. They also have different clinical characteristics in terms of epilepsy, movement disorders, and neurodevelopment compared with children with deletions or intragenic mutations. FOXG1 is a transcriptional factor. It is expressed mainly in the telencephalon and plays a pleiotropic role in the development of the brain. It is a key player in development and territorial specification of the anterior brain. In addition, it maintains the expansion of the neural proliferating pool, and also regulates the pace of neocortical neuronogenic progression. It also facilitates cortical layer and corpus callosum formation. Furthermore, it promotes dendrite elongation and maintains neural plasticity, including dendritic arborization and spine densities in mature neurons. In this review, we summarize the clinical features, molecular genetics, and possible pathogenesis of FOXG1-related syndrome.
Collapse
|
14
|
Xiol C, Vidal S, Pascual-Alonso A, Blasco L, Brandi N, Pacheco P, Gerotina E, O'Callaghan M, Pineda M, Armstrong J. X chromosome inactivation does not necessarily determine the severity of the phenotype in Rett syndrome patients. Sci Rep 2019; 9:11983. [PMID: 31427717 PMCID: PMC6700087 DOI: 10.1038/s41598-019-48385-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/05/2019] [Indexed: 11/24/2022] Open
Abstract
Rett syndrome (RTT) is a severe neurological disorder usually caused by mutations in the MECP2 gene. Since the MECP2 gene is located on the X chromosome, X chromosome inactivation (XCI) could play a role in the wide range of phenotypic variation of RTT patients; however, classical methylation-based protocols to evaluate XCI could not determine whether the preferentially inactivated X chromosome carried the mutant or the wild-type allele. Therefore, we developed an allele-specific methylation-based assay to evaluate methylation at the loci of several recurrent MECP2 mutations. We analyzed the XCI patterns in the blood of 174 RTT patients, but we did not find a clear correlation between XCI and the clinical presentation. We also compared XCI in blood and brain cortex samples of two patients and found differences between XCI patterns in these tissues. However, RTT mainly being a neurological disease complicates the establishment of a correlation between the XCI in blood and the clinical presentation of the patients. Furthermore, we analyzed MECP2 transcript levels and found differences from the expected levels according to XCI. Many factors other than XCI could affect the RTT phenotype, which in combination could influence the clinical presentation of RTT patients to a greater extent than slight variations in the XCI pattern.
Collapse
Affiliation(s)
- Clara Xiol
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Silvia Vidal
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Ainhoa Pascual-Alonso
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Laura Blasco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Núria Brandi
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Paola Pacheco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Edgar Gerotina
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Mar O'Callaghan
- Neurology Service, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Mercè Pineda
- Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Judith Armstrong
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain. .,Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu, Barcelona, Spain. .,CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain.
| | | |
Collapse
|
15
|
Vidal S, Xiol C, Pascual-Alonso A, O'Callaghan M, Pineda M, Armstrong J. Genetic Landscape of Rett Syndrome Spectrum: Improvements and Challenges. Int J Mol Sci 2019; 20:ijms20163925. [PMID: 31409060 PMCID: PMC6719047 DOI: 10.3390/ijms20163925] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/08/2019] [Accepted: 08/10/2019] [Indexed: 02/06/2023] Open
Abstract
Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that primarily affects females, resulting in severe cognitive and physical disabilities, and is one of the most prevalent causes of intellectual disability in females. More than fifty years after the first publication on Rett syndrome, and almost two decades since the first report linking RTT to the MECP2 gene, the research community's effort is focused on obtaining a better understanding of the genetics and the complex biology of RTT and Rett-like phenotypes without MECP2 mutations. Herein, we review the current molecular genetic studies, which investigate the genetic causes of RTT or Rett-like phenotypes which overlap with other genetic disorders and document the swift evolution of the techniques and methodologies employed. This review also underlines the clinical and genetic heterogeneity of the Rett syndrome spectrum and provides an overview of the RTT-related genes described to date, many of which are involved in epigenetic gene regulation, neurotransmitter action or RNA transcription/translation. Finally, it discusses the importance of including both phenotypic and genetic diagnosis to provide proper genetic counselling from a patient's perspective and the appropriate treatment.
Collapse
Affiliation(s)
- Silvia Vidal
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Clara Xiol
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Ainhoa Pascual-Alonso
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - M O'Callaghan
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- Neurology Service, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain
| | - Mercè Pineda
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
| | - Judith Armstrong
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain.
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
| |
Collapse
|
16
|
Salpietro V, Dixon CL, Guo H, Bello OD, Vandrovcova J, Efthymiou S, Maroofian R, Heimer G, Burglen L, Valence S, Torti E, Hacke M, Rankin J, Tariq H, Colin E, Procaccio V, Striano P, Mankad K, Lieb A, Chen S, Pisani L, Bettencourt C, Männikkö R, Manole A, Brusco A, Grosso E, Ferrero GB, Armstrong-Moron J, Gueden S, Bar-Yosef O, Tzadok M, Monaghan KG, Santiago-Sim T, Person RE, Cho MT, Willaert R, Yoo Y, Chae JH, Quan Y, Wu H, Wang T, Bernier RA, Xia K, Blesson A, Jain M, Motazacker MM, Jaeger B, Schneider AL, Boysen K, Muir AM, Myers CT, Gavrilova RH, Gunderson L, Schultz-Rogers L, Klee EW, Dyment D, Osmond M, Parellada M, Llorente C, Gonzalez-Peñas J, Carracedo A, Van Haeringen A, Ruivenkamp C, Nava C, Heron D, Nardello R, Iacomino M, Minetti C, Skabar A, Fabretto A, Raspall-Chaure M, Chez M, Tsai A, Fassi E, Shinawi M, Constantino JN, De Zorzi R, Fortuna S, Kok F, Keren B, Bonneau D, Choi M, Benzeev B, Zara F, Mefford HC, Scheffer IE, Clayton-Smith J, Macaya A, Rothman JE, Eichler EE, Kullmann DM, Houlden H. AMPA receptor GluA2 subunit defects are a cause of neurodevelopmental disorders. Nat Commun 2019; 10:3094. [PMID: 31300657 PMCID: PMC6626132 DOI: 10.1038/s41467-019-10910-w] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 05/22/2019] [Indexed: 01/22/2023] Open
Abstract
AMPA receptors (AMPARs) are tetrameric ligand-gated channels made up of combinations of GluA1-4 subunits encoded by GRIA1-4 genes. GluA2 has an especially important role because, following post-transcriptional editing at the Q607 site, it renders heteromultimeric AMPARs Ca2+-impermeable, with a linear relationship between current and trans-membrane voltage. Here, we report heterozygous de novo GRIA2 mutations in 28 unrelated patients with intellectual disability (ID) and neurodevelopmental abnormalities including autism spectrum disorder (ASD), Rett syndrome-like features, and seizures or developmental epileptic encephalopathy (DEE). In functional expression studies, mutations lead to a decrease in agonist-evoked current mediated by mutant subunits compared to wild-type channels. When GluA2 subunits are co-expressed with GluA1, most GRIA2 mutations cause a decreased current amplitude and some also affect voltage rectification. Our results show that de-novo variants in GRIA2 can cause neurodevelopmental disorders, complementing evidence that other genetic causes of ID, ASD and DEE also disrupt glutamatergic synaptic transmission.
Collapse
Affiliation(s)
- Vincenzo Salpietro
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini", 16147, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16132, Genoa, Italy
| | - Christine L Dixon
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Hui Guo
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, 98195, USA
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, 410083, Hunan, China
| | - Oscar D Bello
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Jana Vandrovcova
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Stephanie Efthymiou
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Reza Maroofian
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Gali Heimer
- Pediatric Neurology Unit, Safra Children's Hospital, Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 526121, Ramat Gan, Israel
| | - Lydie Burglen
- Centre de Référence des Malformations et Maladies Congénitales du Cervelet, Département de Génétique et Embryologie Médicale, APHP, Hôpital Trousseau, 75012, Paris, France
| | - Stephanie Valence
- Centre de Référence des Malformations et Maladies Congénitales du Cervelet, Service de Neurologie Pédiatrique, APHP, Hôpital Trousseau, 75012, Paris, France
| | | | - Moritz Hacke
- Biochemistry Center, Heidelberg University, D-69120, Heidelberg, Germany
| | - Julia Rankin
- Royal Devon and Exeter NHS Foundation Trust, Exeter, EX1 2ED, UK
| | - Huma Tariq
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Estelle Colin
- Department of Biochemistry and Genetics, University Hospital, 49933, Angers, France
- MitoLab, UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, 49100, Angers, France
| | - Vincent Procaccio
- Department of Biochemistry and Genetics, University Hospital, 49933, Angers, France
- MitoLab, UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, 49100, Angers, France
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini", 16147, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16132, Genoa, Italy
| | - Kshitij Mankad
- Great Ormond Street Hospital for Children, London, WC1N 3JH, UK
| | - Andreas Lieb
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Sharon Chen
- Division of Medical Genetics, Northwell Health/Hofstra University SOM, New York, 11020, USA
| | - Laura Pisani
- Division of Medical Genetics, Northwell Health/Hofstra University SOM, New York, 11020, USA
| | - Conceicao Bettencourt
- Department of Clinical and Movement Neurosciences and Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, WC1N 1PJ, UK
| | - Roope Männikkö
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Andreea Manole
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Alfredo Brusco
- Department of Medical Sciences, Medical Genetics Unit, University of Torino, 10126, Torino, Italy
| | - Enrico Grosso
- Department of Medical Sciences, Medical Genetics Unit, University of Torino, 10126, Torino, Italy
| | | | - Judith Armstrong-Moron
- Unit of Medical and Molecular Genetics, University Hospital Sant Joan de Deu Barcelona, 08950, Barcelona, Spain
| | - Sophie Gueden
- Unit of Neuropediatrics, University Hospital, Angers Cedex, 49933, France
| | - Omer Bar-Yosef
- Pediatric Neurology Unit, Safra Children's Hospital, Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 526121, Ramat Gan, Israel
| | - Michal Tzadok
- Pediatric Neurology Unit, Safra Children's Hospital, Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 526121, Ramat Gan, Israel
| | | | | | | | | | | | - Yongjin Yoo
- Department of Biomedical Sciences, Seoul National University, Seoul, 03080, South Korea
| | - Jong-Hee Chae
- Department of Pediatrics, Seoul National University, Seoul, 03080, South Korea
| | - Yingting Quan
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, 410083, Hunan, China
| | - Huidan Wu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, 410083, Hunan, China
| | - Tianyun Wang
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, 98195, USA
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, 410083, Hunan, China
| | - Raphael A Bernier
- Department of Psychiatry, University of Washington, Seattle, WA, 98195, USA
| | - Kun Xia
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, 410083, Hunan, China
| | - Alyssa Blesson
- Center for Autism and Related Disorders, Kennedy Krieger Institute, Baltimore, Maryland, 21211, USA
| | - Mahim Jain
- Center for Autism and Related Disorders, Kennedy Krieger Institute, Baltimore, Maryland, 21211, USA
| | - Mohammad M Motazacker
- Department of Clinical Genetics, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, Netherlands
| | - Bregje Jaeger
- Department of Pediatric Neurology, Amsterdam UMC, 1105, Amsterdam, Netherlands
| | - Amy L Schneider
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, 3084, Australia
| | - Katja Boysen
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, 3084, Australia
| | - Alison M Muir
- Department of Pediatrics, University of Washington, Seattle, WA, 98195, USA
| | - Candace T Myers
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, 98195, USA
| | | | - Lauren Gunderson
- Department of Clinical Genomics, Mayo Clinic, Rochester, 55902, MN, USA
| | | | - Eric W Klee
- Department of Clinical Genomics, Mayo Clinic, Rochester, 55902, MN, USA
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, K1H 8L1, Canada
| | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, K1H 8L1, Canada
- Department of Human Genetics, McGill University Health Centre, Montréal, QC, H4A 3J1, Canada
- Genome Québec Innovation Center, Montréal, QC, H3A 0G1, Canada
| | - Mara Parellada
- Child and Adolescent Psychiatry Department, Hospital General Universitario Gregorio Marañón, School of Medicine, Universidad Complutense, IiSGM, CIBERSAM, 28007, Madrid, Spain
| | - Cloe Llorente
- Institute of Psychiatry and Mental Health, Hospital General Universitario Gregorio Maranon, Universidad Complutense, CIBERSAM, 28007, Madrid, Spain
| | - Javier Gonzalez-Peñas
- Hospital Gregorio Maranon, IiSGM, School of Medicine, Calle Dr Esquerdo, 46, 28007, Madrid, Spain
| | - Angel Carracedo
- Grupo de Medicina Xenómica, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), CIMUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
- Fundación Pública Galega de Medicina Xenómica- IDIS- Servicio Galego de Saúde (SERGAS), 15706, 15782, Santiago de Compostela, Spain
| | - Arie Van Haeringen
- Department of Clinical Genetics, Leiden University Medical Center, 2333 ZA, Leiden, Netherlands
| | - Claudia Ruivenkamp
- Department of Clinical Genetics, Leiden University Medical Center, 2333 ZA, Leiden, Netherlands
| | - Caroline Nava
- Department of Genetics, Assistance Publique - Hôpitaux de Paris, University Hôpital Pitié-Salpêtrière, 75013, Paris, France
| | - Delphine Heron
- Department of Genetics, Assistance Publique - Hôpitaux de Paris, University Hôpital Pitié-Salpêtrière, 75013, Paris, France
| | - Rosaria Nardello
- Department of Health Promotion,Mother and Child Care, Internal Medicine and Medical Specialities "G. D'Alessandro", University of Palermo, 90133, Palermo, Italy
| | - Michele Iacomino
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto "Giannina Gaslini", 16147, Genova, Italy
| | - Carlo Minetti
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini", 16147, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16132, Genoa, Italy
| | - Aldo Skabar
- Institute for Maternal and Child Health, IRCCS "Burlo Garofolo", University of Trieste, 34134, Trieste, Italy
| | - Antonella Fabretto
- Institute for Maternal and Child Health, IRCCS "Burlo Garofolo", University of Trieste, 34134, Trieste, Italy
| | - Miquel Raspall-Chaure
- Department of Pediatric Neurology, University Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035, Barcelona, Spain
| | - Michael Chez
- Neuroscience Medical Group, 1625 Stockton Boulevard, Suite 104, Sacramento, CA, 95816, USA
| | - Anne Tsai
- Department of Genetics and Inherited Metabolic diseases, Children's Hospital Colorado, Aurora, CO, 80045, USA
| | - Emily Fassi
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Marwan Shinawi
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - John N Constantino
- William Greenleaf Eliot Division of Child & Adolescent Psychiatry, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Rita De Zorzi
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34134, Trieste, Italy
| | - Sara Fortuna
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34134, Trieste, Italy
| | - Fernando Kok
- Neurogenetics Unit, Department of Neurology, University of Sao Paulo, Sao Paulo, 01308-000, Brazil
- Mendelics Genomic Analysis, Sao Paulo, SP, 04013-000, Brazil
| | - Boris Keren
- Department of Genetics, Assistance Publique - Hôpitaux de Paris, University Hôpital Pitié-Salpêtrière, 75013, Paris, France
| | - Dominique Bonneau
- Department of Biochemistry and Genetics, University Hospital, 49933, Angers, France
- MitoLab, UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, 49100, Angers, France
| | - Murim Choi
- Department of Biomedical Sciences, Seoul National University, Seoul, 03080, South Korea
| | - Bruria Benzeev
- Pediatric Neurology Unit, Safra Children's Hospital, Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 526121, Ramat Gan, Israel
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto "Giannina Gaslini", 16147, Genova, Italy
| | - Heather C Mefford
- Department of Pediatrics, University of Washington, Seattle, WA, 98195, USA
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, 3084, Australia
| | - Jill Clayton-Smith
- Centre for Genomic Medicine, Manchester Academic Health Sciences Centre, Central Manchester University Hospitals NHS Foundation Trust, Lancashire, M13 9WL, UK
- Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Manchester, M13 9WL, UK
| | - Alfons Macaya
- Department of Pediatric Neurology, University Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035, Barcelona, Spain
| | - James E Rothman
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Dimitri M Kullmann
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK.
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK.
| |
Collapse
|
17
|
Vidal S, Brandi N, Pacheco P, Maynou J, Fernandez G, Xiol C, Pascual-Alonso A, Pineda M, Armstrong J, Garcia-Cazorla À, del Carmen Serrano Munuera M, García SC, Troncoso M, Fariña G, García Peñas JJ, Fournier BG, León SR, Guitart M, Baena N, de Nanclares GP, Oci IO, Gutiérrez-Delicado E, Abarrategui B, Barroso E, Santos-Simarro F, Lapunzina P, García FJ, Acedo JM, García A, Martinez MA, Martínez-Bermejo A. The most recurrent monogenic disorders that overlap with the phenotype of Rett syndrome. Eur J Paediatr Neurol 2019; 23:609-620. [PMID: 31105003 DOI: 10.1016/j.ejpn.2019.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/12/2019] [Accepted: 04/28/2019] [Indexed: 12/30/2022]
Abstract
Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that is caused by mutations in the MECP2 gene; however, defects in other genes (CDKL5 and FOXG1) can lead to presentations that resemble classic RTT, although they are not completely identical. Here, we attempted to identify other monogenic disorders that share features of RTT. A total of 437 patients with a clinical diagnosis of RTT-like were studied; in 242 patients, a custom panel with 17 genes related to an RTT-like phenotype was run via a HaloPlex-Target-Enrichment-System. In the remaining 195 patients, a commercial TruSight-One-Sequencing-Panel was analysed. A total of 40 patients with clinical features of RTT had variants which affect gene function in six genes associated with other monogenic disorders. Twelve patients had variants in STXBP1, nine in TCF4, six in SCN2A, five in KCNQ2, four in MEF2C and four in SYNGAP1. Genetic studies using next generation sequencing (NGS) allowed us to study a larger number of genes associated with RTT-like simultaneously, providing a genetic diagnosis for a wider group of patients. These new findings provide the clinician with more information and clues that could help in the prevention of future symptoms or in pharmacologic therapy.
Collapse
Affiliation(s)
- S Vidal
- Sant Joan de Déu Research Foundation, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - N Brandi
- School of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - P Pacheco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - J Maynou
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - G Fernandez
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - C Xiol
- Sant Joan de Déu Research Foundation, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - A Pascual-Alonso
- Sant Joan de Déu Research Foundation, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain
| | - M Pineda
- Sant Joan de Déu Research Foundation, Barcelona, Spain
| | | | - J Armstrong
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain; Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain; CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Vidal S, Pascual-Alonso A, Rabaza-Gairí M, Gerotina E, Brandi N, Pacheco P, Xiol C, Pineda M, Armstrong J. Characterization of large deletions of the MECP2 gene in Rett syndrome patients by gene dosage analysis. Mol Genet Genomic Med 2019; 7:e793. [PMID: 31206249 PMCID: PMC6687651 DOI: 10.1002/mgg3.793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/24/2019] [Accepted: 05/16/2019] [Indexed: 12/31/2022] Open
Abstract
Background Rett syndrome (RTT) is a developmental disorder with an early onset and X‐linked dominant inheritance pattern. It is first recognized in infancy and is seen almost always in girls, but it may be seen in boys on rare occasions. Typical RTT is caused by de novo mutations of the gene MECP2 (OMIM*300005), and atypical forms of RTT can be caused by mutations of the CDKL5 (OMIM*300203) and FOXG1 (OMIM*164874) genes. Methods Approximately 5% of the mutations detected in MECP2 are large rearrangements that range from exons to the entire gene. Here, we have characterized the deletions detected by multiplex ligation‐dependent probe amplification (MLPA) in the gene MECP2 of 21 RTT patients. Breakpoints were delineated by DNA‐qPCR until the amplification of the deleted allele by long‐PCR was possible. Results This methodology enabled us to characterize deletions ranging from 1,235 bp to 85 kb, confirming the partial or total deletion of the MECP2 gene in all these patients. Additionally, our cases support the evidence claiming that most of these breakpoints occur in some restricted regions of the MECP2 gene. Conclusion These molecular data together with the clinical information enable us to propose a genotype–phenotype correlation, which is essential for providing genetic counseling.
Collapse
Affiliation(s)
- Silvia Vidal
- Sant Joan de Déu Research Foundation, Barcelona, Spain.,Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain
| | - Ainhoa Pascual-Alonso
- Sant Joan de Déu Research Foundation, Barcelona, Spain.,Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain
| | - Marc Rabaza-Gairí
- Sant Joan de Déu Research Foundation, Barcelona, Spain.,Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain
| | - Edgar Gerotina
- Sant Joan de Déu Research Foundation, Barcelona, Spain.,Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain
| | - Nuria Brandi
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Paola Pacheco
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Clara Xiol
- Sant Joan de Déu Research Foundation, Barcelona, Spain.,Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain
| | - Mercè Pineda
- Sant Joan de Déu Research Foundation, Barcelona, Spain
| | | | - Judith Armstrong
- Sant Joan de Déu Research Institute (IRSJD), Hospital Sant Joan de Déu, Esplugues de Lobregat (Barcelona), Spain.,Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain.,CIBER-ER (Biomedical Network Research Center for Rare Diseases), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
19
|
Operto FF, Mazza R, Pastorino GMG, Verrotti A, Coppola G. Epilepsy and genetic in Rett syndrome: A review. Brain Behav 2019; 9:e01250. [PMID: 30929312 PMCID: PMC6520293 DOI: 10.1002/brb3.1250] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/03/2019] [Accepted: 02/10/2019] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Rett syndrome (RTT) is a severe X-linked neurodevelopmental disorder that primarily affects girls, with an incidence of 1:10,000-20,000. The diagnosis is based on clinical features: an initial period of apparently normal development (ages 6-12 months) followed by a rapid decline with regression of acquired motor skills, loss of spoken language and purposeful hand use, onset of hand stereotypes, abnormal gait, and growth failure. The course of the disease, in its classical form, is characterized by four stages. Three different atypical variants of the disease have been defined. Epilepsy has been reported in 60%-80% of patients with RTT; it differs among the various phenotypes and genotypes and its severity is an important contributor to the clinical severity of the disease. METHODS In this manuscript we reviewed literature on RTT, focusing on the different genetic entities, the correlation genotype-phenotype, and the peculiar epileptic phenotype associated to each of them. RESULTS Mutations in MECP2 gene, located on Xq28, account for 95% of typical RTT cases and 73.2% of atypical RTT. CDKL5 and FOXG1 are other genes identified as causative genes in atypical forms of RTT. In the last few years, a lot of new genes have been identified as causative genes for RTT phenotype. CONCLUSIONS Recognizing clinical and EEG patterns in different RTT variants may be useful in diagnosis and management of these patients.
Collapse
Affiliation(s)
- Francesca Felicia Operto
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Roberta Mazza
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | | | - Alberto Verrotti
- Department of Pediatrics, University of L'Aquila, Coppito, Italy
| | - Giangennaro Coppola
- Child and Adolescent Neuropsychiatry, Medical School, University of Salerno, Fisciano, Italy
| |
Collapse
|
20
|
Alexandrou A, Papaevripidou I, Alexandrou IM, Theodosiou A, Evangelidou P, Kousoulidou L, Tanteles G, Christophidou‐Anastasiadou V, Sismani C. De novo mosaic MECP2 mutation in a female with Rett syndrome. Clin Case Rep 2019; 7:366-370. [PMID: 30847208 PMCID: PMC6389470 DOI: 10.1002/ccr3.1985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/30/2018] [Accepted: 12/11/2018] [Indexed: 01/08/2023] Open
Abstract
We describe a female with Rett syndrome carrying a rare de novo mosaic nonsense mutation on MECP2 gene, with random X-chromosome inactivation. Rett syndrome severity in females depends on mosaicism level and tissue specificity, X-chromosome inactivation, epigenetics and environment. Rett syndrome should be considered in both males and females.
Collapse
Affiliation(s)
- Angelos Alexandrou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ioanna Maria Alexandrou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Athina Theodosiou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Paola Evangelidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Ludmila Kousoulidou
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - George Tanteles
- Department of Clinical GeneticsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
| | - Violetta Christophidou‐Anastasiadou
- Department of Clinical GeneticsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Archbishop Makarios III Medical CentreNicosiaCyprus
| | - Carolina Sismani
- Department of Cytogenetics and GenomicsThe Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- The Cyprus School of Molecular MedicineNicosiaCyprus
| |
Collapse
|
21
|
Kyriakopoulos P, McNiven V, Carter MT, Humphreys P, Dyment D, Fantaneanu TA. Atypical Rett Syndrome and Intractable Epilepsy With Novel GRIN2B Mutation. Child Neurol Open 2018; 5:2329048X18787946. [PMID: 30151416 PMCID: PMC6108011 DOI: 10.1177/2329048x18787946] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/05/2018] [Accepted: 06/15/2018] [Indexed: 11/16/2022] Open
Affiliation(s)
- Paulina Kyriakopoulos
- Division of Neurology, The Ottawa Hospital Civic Campus, Ottawa, Ontario, Canada.,co-authors who contributed equally
| | - Vanda McNiven
- Division of Clinical Genetics and Metabolics, SickKids, Toronto, Ontario, Canada.,co-authors who contributed equally
| | - Melissa T Carter
- Department of Genetics, The Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Peter Humphreys
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - David Dyment
- Department of Genetics, The Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Tadeu A Fantaneanu
- Division of Neurology, The Ottawa Hospital Civic Campus, Ottawa, Ontario, Canada
| |
Collapse
|
22
|
Cortès-Saladelafont E, Molero-Luis M, Cuadras D, Casado M, Armstrong-Morón J, Yubero D, Montoya J, Artuch R, García-Cazorla À. Gamma-aminobutyric acid levels in cerebrospinal fluid in neuropaediatric disorders. Dev Med Child Neurol 2018; 60:780-792. [PMID: 29577258 DOI: 10.1111/dmcn.13746] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/31/2018] [Indexed: 11/29/2022]
Abstract
AIM Gamma-aminobutyric acid (GABA) is a major modulator in brain maturation and its role in many different neurodevelopmental disorders has been widely reported. Although the involvement of GABA in different disorders has been related to its regulatory function as an inhibitory neurotransmitter in the mature brain, co-transmitter, and signalling molecule, little is known about its role as a clinical biomarker in neuropaediatric disorders. The aim of this study is to report the cerebrospinal fluid (CSF) free-GABA concentrations in a large cohort of patients (n=85) with different neurological disorders. METHOD GABA was measured in the CSF of neuropaediatric patients using capillary electrophoresis with laser-induced fluorescence detection. Other neurotransmitters (amino acids and monoamines) were also analysed. RESULTS GABA concentrations in CSF were abnormal, with a greater frequency (44%) than monoamines (20%) in neuropaediatric patients compared with our reference values. Although we included a few patients with inborn errors of metabolism, GABA levels in CSF were more frequently abnormal in metabolic disorders than in other nosological groups. INTERPRETATION Our work suggests further research into brain GABAergic status in neuropaediatric disorders, which could also lead to new therapeutic strategies. WHAT THIS PAPER ADDS Homeostasis of GABA seems more vulnerable than that of monoamines in the developing brain. The highest GABA levels are found in the primary GABA neurotransmitter disorder SSADH deficiency. GABA alterations are not specific for any clinical or neuroimaging presentation.
Collapse
Affiliation(s)
- Elisenda Cortès-Saladelafont
- Department of Neurology, Neurometabolic Unit and Synaptic Metabolism Laboratory, Hospital Sant Joan de Déu, Barcelona, Spain.,Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain
| | - Marta Molero-Luis
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics and Biochemistry, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Daniel Cuadras
- Statistics Department, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Mercedes Casado
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics and Biochemistry, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Judith Armstrong-Morón
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics and Biochemistry, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Dèlia Yubero
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics and Biochemistry, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Julio Montoya
- Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry, Molecular and Cellular Biology, Universidad de Zaragoza, Zaragoza, Spain
| | - Rafael Artuch
- Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Genetics and Biochemistry, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Àngels García-Cazorla
- Department of Neurology, Neurometabolic Unit and Synaptic Metabolism Laboratory, Hospital Sant Joan de Déu, Barcelona, Spain.,Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain.,Centro de In.vestigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | |
Collapse
|
23
|
Abstract
PURPOSE OF REVIEW This article reviews the current molecular genetic studies, which investigate the genetic causes of Rett syndrome or Rett-like phenotypes without a MECP2 mutation. RECENT FINDINGS As next generation sequencing becomes broadly available, especially whole exome sequencing is used in clinical diagnosis of the genetic causes of a wide spectrum of intellectual disability, autism, and encephalopathies. Patients who were diagnosed with Rett syndrome or Rett-like syndrome because of their phenotype but were negative for mutations in the MECP2, CDKL5 or FOXG1 genes were subjected to whole exome sequencing and the results of the last few years revealed yet 69 different genes. Many of these genes are involved in epigenetic gene regulation, chromatin shaping, neurotransmitter action or RNA transcription/translation. Genetic data also allows to investigate the individual genetic background of an individual patient, which can modify the severity of a genetic disorder. SUMMARY We conclude that the Rett syndrome phenotype has a much broader underlying genetic cause and the typical phenotype overlap with other genetic disorders. For proper genetic counselling, patient perspective and treatment it is important to include both phenotype and genetic information.
Collapse
|