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Mbachu CNP, Mbachu II, Hagerman R. A Comprehensive Review of Fragile X Syndrome and Fragile X Premutation Associated Conditions in Africa. Genes (Basel) 2024; 15:683. [PMID: 38927619 PMCID: PMC11203117 DOI: 10.3390/genes15060683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/17/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024] Open
Abstract
Fragile X syndrome (FXS) is a genetic disorder caused by a mutation in the fragile X messenger ribonucleoprotein 1 (FMR1) gene and known to be a leading cause of inherited intellectual disability globally. It results in a range of intellectual, developmental, and behavioral problems. Fragile X premutation-associated conditions (FXPAC), caused by a smaller CGG expansion (55 to 200 CGG repeats) in the FMR1 gene, are linked to other conditions that increase morbidity and mortality for affected persons. Limited research has been conducted on the burden, characteristics, diagnosis, and management of these conditions in Africa. This comprehensive review provides an overview of the current literature on FXS and FXPAC in Africa. The issues addressed include epidemiology, clinical features, discrimination against affected persons, limited awareness and research, and poor access to resources, including genetic services and treatment programs. This paper provides an in-depth analysis of the existing worldwide data for the diagnosis and treatment of fragile X disorders. This review will improve the understanding of FXS and FXPAC in Africa by incorporating existing knowledge, identifying research gaps, and potential topics for future research to enhance the well-being of individuals and families affected by FXS and FXPAC.
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Affiliation(s)
- Chioma N. P. Mbachu
- Department of Paediatrics, Faculty of Medicine, College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus, Nnewi 435101, Nigeria
- MIND Institute, University of California Davis, Sacramento, CA 95817, USA
| | - Ikechukwu Innocent Mbachu
- Department of Obstetrics and Gynaecology, Faculty of Medicine, College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus, Nnewi 435101, Nigeria;
| | - Randi Hagerman
- MIND Institute, University of California Davis, Sacramento, CA 95817, USA
- Department of Pediatrics, University of California Davis Health, Sacramento, CA 95817, USA
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2
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Bekheet MHY, Mansour LA, Elkaffas RH, Kamel MA, Elmonem MA. Serum matrix metalloproteinase-9 (MMP9) and amyloid-beta protein precursor (APP) as potential biomarkers in children with Fragile-X syndrome: A cross sectional study. Clin Biochem 2023; 121-122:110659. [PMID: 37797798 DOI: 10.1016/j.clinbiochem.2023.110659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/29/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023]
Abstract
INTRODUCTION Fragile-X syndrome(FXS) is a neurological disease caused by abnormal repeats in the 5'untranslated region of the FMR1 gene leading to a defective fragile-X-messenger-ribonucleoprotein-1 (FMRP). Although relatively common in children, it is usually under-diagnosed especially in developing countries where genetic screening is not routinely practiced. So far, FXS lacks a laboratory biomarker that can be used for screening, severity scoring or therapeutic monitoring of potential new treatments. METHODS 110 subjects were recruited; 80 male children with suspected FXS and 30 matched healthy children. We evaluated the clinical utility of serum matrix metalloproteinase-9(MMP9) and amyloid-beta protein precursor(APP) as potential biomarkers for FXS. RESULTS Out of 80 suspected children, 14 had full mutation, 8 had the premutation and 58 children had normal genotypes. No statistically-significant difference was detected between children with different genotypes concerning age of onset(P = 0.658), main clinical presentation(P = 0.388), clinical severity-score(P = 0.799), patient's disease-course(P = 0.719) and intellectual disability(P = 0.351). Both MMP9 and APP showed a statistically significant difference when comparing different genotype subgroups(P = 0.019 and < 0.001, respectively). Clinically, MMP9 levels were highest in children presenting with language defects, while APP was highest in children with neurodevelopmental delay. In receiver operating curve analysis, comparing full and premutation with the normal genotype group, MMP9 has an area-under-the-curve of 0.701(95 % CI 0.557-0.845), while APP was marginally better at 0.763(95 % CI 0.620-0.906). When combined together, elevated MMP9 or APP had excellent sensitivity > 95 % for picking-up FXS cases in the clinical setting. CONCLUSIONS Screening for circulating biomarkers in the absence of FXS genetic diagnosis is justified. Our study is the first to evaluate both MMP9 and APP in FXS suspected children in a clinical setting and to assess their correlation with disease presentation and severity.
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Affiliation(s)
- Mohamed H Y Bekheet
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Lamiaa A Mansour
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Rasha H Elkaffas
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mona A Kamel
- Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mohamed A Elmonem
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt.
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Elhawary NA, AlJahdali IA, Abumansour IS, Azher ZA, Falemban AH, Madani WM, Alosaimi W, Alghamdi G, Sindi IA. Phenotypic variability to medication management: an update on fragile X syndrome. Hum Genomics 2023; 17:60. [PMID: 37420260 DOI: 10.1186/s40246-023-00507-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023] Open
Abstract
This review discusses the discovery, epidemiology, pathophysiology, genetic etiology, molecular diagnosis, and medication-based management of fragile X syndrome (FXS). It also highlights the syndrome's variable expressivity and common comorbid and overlapping conditions. FXS is an X-linked dominant disorder associated with a wide spectrum of clinical features, including but not limited to intellectual disability, autism spectrum disorder, language deficits, macroorchidism, seizures, and anxiety. Its prevalence in the general population is approximately 1 in 5000-7000 men and 1 in 4000-6000 women worldwide. FXS is associated with the fragile X messenger ribonucleoprotein 1 (FMR1) gene located at locus Xq27.3 and encodes the fragile X messenger ribonucleoprotein (FMRP). Most individuals with FXS have an FMR1 allele with > 200 CGG repeats (full mutation) and hypermethylation of the CpG island proximal to the repeats, which silences the gene's promoter. Some individuals have mosaicism in the size of the CGG repeats or in hypermethylation of the CpG island, both produce some FMRP and give rise to milder cognitive and behavioral deficits than in non-mosaic individuals with FXS. As in several monogenic disorders, modifier genes influence the penetrance of FMR1 mutations and FXS's variable expressivity by regulating the pathophysiological mechanisms related to the syndrome's behavioral features. Although there is no cure for FXS, prenatal molecular diagnostic testing is recommended to facilitate early diagnosis. Pharmacologic agents can reduce some behavioral features of FXS, and researchers are investigating whether gene editing can be used to demethylate the FMR1 promoter region to improve patient outcomes. Moreover, clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 and developed nuclease defective Cas9 (dCas9) strategies have promised options of genome editing in gain-of-function mutations to rewrite new genetic information into a specified DNA site, are also being studied.
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Affiliation(s)
- Nasser A Elhawary
- Department of Medical Genetics, College of Medicine, Umm Al-Qura University, Mecca, 21955, Saudi Arabia.
| | - Imad A AlJahdali
- Department of Community Medicine, College of Medicine, Umm Al-Qura University, Mecca, Saudi Arabia
| | - Iman S Abumansour
- Department of Medical Genetics, College of Medicine, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Zohor A Azher
- Department of Medical Genetics, College of Medicine, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Alaa H Falemban
- Department of Pharmacology and Toxicology, College of Medicine, Umm Al-Qura University, Mecca, 24382, Saudi Arabia
| | - Wefaq M Madani
- Department of Hematology and Immunology, Faculty of Medicine, Umm Al-Qura University, Mecca, Saudi Arabia
| | - Wafaa Alosaimi
- Department of Hematology, Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Ghydda Alghamdi
- Department of Medical Genetics, College of Medicine, Umm Al-Qura University, Mecca, 21955, Saudi Arabia
| | - Ikhlas A Sindi
- Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
- Preparatory Year Program, Batterjee Medical College, Jeddah, 21442, Saudi Arabia
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Carter MT, Srour M, Au PYB, Buhas D, Dyack S, Eaton A, Inbar-Feigenberg M, Howley H, Kawamura A, Lewis SME, McCready E, Nelson TN, Vallance H. Genetic and metabolic investigations for neurodevelopmental disorders: position statement of the Canadian College of Medical Geneticists (CCMG). J Med Genet 2023; 60:523-532. [PMID: 36822643 DOI: 10.1136/jmg-2022-108962] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/27/2023] [Indexed: 02/25/2023]
Abstract
PURPOSE AND SCOPE The aim of this position statement is to provide recommendations for clinicians regarding the use of genetic and metabolic investigations for patients with neurodevelopmental disorders (NDDs), specifically, patients with global developmental delay (GDD), intellectual disability (ID) and/or autism spectrum disorder (ASD). This document also provides guidance for primary care and non-genetics specialists caring for these patients while awaiting consultation with a clinical geneticist or metabolic specialist. METHODS OF STATEMENT DEVELOPMENT A multidisciplinary group reviewed existing literature and guidelines on the use of genetic and metabolic investigations for the diagnosis of NDDs and synthesised the evidence to make recommendations relevant to the Canadian context. The statement was circulated for comment to the Canadian College of Medical Geneticists (CCMG) membership-at-large and to the Canadian Pediatric Society (Mental Health and Developmental Disabilities Committee); following incorporation of feedback, it was approved by the CCMG Board of Directors on 1 September 2022. RESULTS AND CONCLUSIONS Chromosomal microarray is recommended as a first-tier test for patients with GDD, ID or ASD. Fragile X testing should also be done as a first-tier test when there are suggestive clinical features or family history. Metabolic investigations should be done if there are clinical features suggestive of an inherited metabolic disease, while the patient awaits consultation with a metabolic physician. Exome sequencing or a comprehensive gene panel is recommended as a second-tier test for patients with GDD or ID. Genetic testing is not recommended for patients with NDDs in the absence of GDD, ID or ASD, unless accompanied by clinical features suggestive of a syndromic aetiology or inherited metabolic disease.
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Affiliation(s)
| | - Myriam Srour
- Division of Neurology, McGill University Health Centre, Montreal, Québec, Canada
- Department of Pediatrics, McGill University, Montréal, QC, Canada
| | - Ping-Yee Billie Au
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Daniela Buhas
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, McGill University, Montreal, Québec, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Sarah Dyack
- Division of Medical Genetics, IWK Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Dalhousie University, Halifax, NS, Canada
| | - Alison Eaton
- Department of Medical Genetics, Stollery Children's Hospital, Edmonton, Alberta, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Michal Inbar-Feigenberg
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Heather Howley
- Office of Research Services, CHEO Research Institute, Ottawa, Ontario, Canada
| | - Anne Kawamura
- Division of Developmental Pediatrics, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada
- Mental Health and Developmental Disability Committee, Canadian Pediatric Society, Ottawa, ON, Canada
- Canadian Paediatric Society, Toronto, Ontario, Canada
| | - Suzanne M E Lewis
- Department of Medical Genetics, BC Children's and Women's Hospital, Vancouver, British Columbia, Canada
| | - Elizabeth McCready
- Department of Pathology and Molecular Medicine, McMaster University, McMaster University, Hamilton, ON, Canada, Hamilton, Ontario, Canada
- Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences Centre, Hamilton, ON, Canada
| | - Tanya N Nelson
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hilary Vallance
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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Evaluation of Individuals with Non-Syndromic Global Developmental Delay and Intellectual Disability. CHILDREN 2023; 10:children10030414. [PMID: 36979972 PMCID: PMC10047567 DOI: 10.3390/children10030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023]
Abstract
Global Developmental Delay (GDD) and Intellectual Disability (ID) are two of the most common presentations encountered by physicians taking care of children. GDD/ID is classified into non-syndromic GDD/ID, where GDD/ID is the sole evident clinical feature, or syndromic GDD/ID, where there are additional clinical features or co-morbidities present. Careful evaluation of children with GDD and ID, starting with detailed history followed by a thorough examination, remain the cornerstone for etiologic diagnosis. However, when initial history and examination fail to identify a probable underlying etiology, further genetic testing is warranted. In recent years, genetic testing has been shown to be the single most important diagnostic modality for clinicians evaluating children with non-syndromic GDD/ID. In this review, we discuss different genetic testing currently available, review common underlying copy-number variants and molecular pathways, explore the recent evidence and recommendations for genetic evaluation and discuss an approach to the diagnosis and management of children with non-syndromic GDD and ID.
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Nagarathinam I, Chong SS, B. K. T, Justin Margret J, Venkataraman V, Natarajan Padmavathy K, Srisailapathy CRS. FMR1 gene CGG repeat distribution among the three individual cohorts with intellectual disability, autism, and primary ovarian insufficiency from Tamil Nadu, Southern India. ADVANCED GENETICS (HOBOKEN, N.J.) 2021; 2:e10048. [PMID: 36618123 PMCID: PMC9744524 DOI: 10.1002/ggn2.10048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Fragile X syndrome is the most common genetic cause of intellectual disability (ID) and is also well known to have a role in primary ovarian insufficiency (POI) and fragile X-associated tremor ataxia syndrome (FXTAS) that expresses across generations. The objective was to compare the CGG repeat variants in FMR1 gene among three correlating cohorts of ID, autism and idiopathic POI. Thirty-six patients with ID, 12 with autism spectrum disorder (ASD) and 13 females with idiopathic POI were screened for FMR1 CGG repeat size by fluorescent methylation-specific PCR and GeneScan analysis, irrespective of Hagerman checklist clinical scores. Among 29 males and seven females, 11 FMR1 allelic variants ranging from 21 to >200 CGG repeats were observed. Three (CF2-3, 39-5, 44-2) out of 29 males had full mutation alleles accounting for a 10.34% incidence of FXS among idiopathic ID males. One of them was a mosaic for CGG repeats with both premutation and full mutation alleles. The frequency of fragile X syndrome is high among patients with idiopathic ID; they also had a high score for the clinical check list. A cascade testing that begins with checklist evaluation prior to DNA analysis will be cost-effective for establishing early diagnosis in South India. With the huge disease burden, there is a need for the establishment of more molecular diagnostics and self-help groups for fragile X syndrome.
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Affiliation(s)
- Indhumathi Nagarathinam
- Department of Genetics, Dr. ALM Post Graduate Institute of Basic Medical SciencesUniversity of MadrasChennaiIndia,Department of Medical Genetics, Laboratory Services, Apollo Main HospitalChennaiIndia
| | - Samuel S. Chong
- Department of Pediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore,Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
| | - Thelma B. K.
- Department of GeneticsUniversity of DelhiNew DelhiIndia
| | - Jeffrey Justin Margret
- Department of Genetics, Dr. ALM Post Graduate Institute of Basic Medical SciencesUniversity of MadrasChennaiIndia
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Erbs E, Fenger-Grøn J, Jacobsen CM, Lildballe DL, Rasmussen M. Spontaneous rescue of a FMR1 repeat expansion and review of deletions in the FMR1 non-coding region. Eur J Med Genet 2021; 64:104244. [PMID: 34022415 DOI: 10.1016/j.ejmg.2021.104244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 04/16/2021] [Accepted: 05/02/2021] [Indexed: 12/07/2022]
Abstract
Fragile X syndrome (FXS) is caused by CGG-repeat expansion in the 5' UTR of FMR1 of >200 repeats. Rarely, FXS is caused by deletions; however, it is not clear whether deletions including only the non-coding region of FMR1 are pathogenic. We report a deletion in the 5' UTR of FMR1 in an unaffected male infant and review 12 reported deletions involving only the non-coding region of FMR1. Genetic testing was requested in a male infant born to a mother harbouring a FMR1 full mutation. The maternal grandmother carried a FMR1 premutation. FMR1 CGG repeats were analysed using repeat-primed PCR. Only a short PCR fragment was amplified and subsequent Sanger sequencing detected an 88 bp deletion in hemizygous form. The deletion included all CGG repeats and flanking sequences but no FMR1 exons. Linkage analysis using STR markers revealed that the deletion had occurred on the allele, which was expanded in the mother and the maternal grandmother. Reverse transcription and quantitative PCR showed normal FMR1 mRNA levels. Grønskov et al. reported a 157 bp deletion of all CGG repeats and flanking sequences in a female without FXS hemizygous for the FMR1 gene due to a deletion on the other X chromosome. Protein expression was unaffected by the deletion. The reported deletion comprises the deletion detected in the male infant. At almost 2 years of age he is unaffected. Based on these observations and the normal FMR1 mRNA level, we conclude that a spontaneous rescue of an FMR1 repeat expansion has occurred.
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Affiliation(s)
- Emilie Erbs
- Department of Clinical Genetics, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark.
| | - Jesper Fenger-Grøn
- Department of Paediatrics, Lillebaelt Hospital, University Hospital of Southern Denmark, Kolding, Denmark
| | - Cecilie Mondrup Jacobsen
- Department of Clinical Genetics, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark
| | - Dorte Launholt Lildballe
- Department of Clinical Genetics, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark
| | - Maria Rasmussen
- Department of Clinical Genetics, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark; Department of Regional Health Research, University of Southern Denmark, Odense M, Denmark
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Abstract
Neurodevelopmental disorders are the most prevalent chronic medical conditions encountered in pediatric primary care. In addition to identifying appropriate descriptive diagnoses and guiding families to evidence-based treatments and supports, comprehensive care for individuals with neurodevelopmental disorders includes a search for an underlying etiologic diagnosis, primarily through a genetic evaluation. Identification of an underlying genetic etiology can inform prognosis, clarify recurrence risk, shape clinical management, and direct patients and families to condition-specific resources and supports. Here we review the utility of genetic testing in patients with neurodevelopmental disorders and describe the three major testing modalities and their yields - chromosomal microarray, exome sequencing (with/without copy number variant calling), and FMR1 CGG repeat analysis for fragile X syndrome. Given the diagnostic yield of genetic testing and the potential for clinical and personal utility, there is consensus that genetic testing should be offered to all patients with global developmental delay, intellectual disability, and/or autism spectrum disorder. Despite this recommendation, data suggest that a minority of children with autism spectrum disorder and intellectual disability have undergone genetic testing. To address this gap in care, we describe a structured but flexible approach to facilitate integration of genetic testing into clinical practice across pediatric specialties and discuss future considerations for genetic testing in neurodevelopmental disorders to prepare pediatric providers to care for patients with such diagnoses today and tomorrow.
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Affiliation(s)
- Juliann M. Savatt
- Autism & Developmental Medicine Institute, Geisinger, Danville, PA, United States
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Verdura E, Pérez-Cano L, Sabido-Vera R, Guney E, Hyvelin JM, Durham L, Gomez-Mancilla B. Heterogeneity in Fragile X Syndrome Highlights the Need for Precision Medicine-Based Treatments. Front Psychiatry 2021; 12:722378. [PMID: 34658958 PMCID: PMC8514715 DOI: 10.3389/fpsyt.2021.722378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/01/2021] [Indexed: 11/21/2022] Open
Abstract
Fragile X syndrome (FXS) is the most frequent monogenic cause of autism or intellectual disability, and research on its pathogenetic mechanisms has provided important insights on this neurodevelopmental condition. Nevertheless, after 30 years of intense research, efforts to develop treatments have been mostly unsuccessful. The aim of this review is to compile evidence from existing research pointing to clinical, genetic, and therapeutic response heterogeneity in FXS and highlight the need of implementing precision medicine-based treatments. We comment on the high genetic and phenotypic heterogeneity present in FXS, as a contributing factor to the difficulties found during drug development. Given that several clinical trials have showed a non-negligeable fraction of positive responders to drugs targeting core FXS symptoms, we propose that success of clinical trials can be achieved by tackling the underlying heterogeneity in FXS by accurately stratifying patients into drug-responder subpopulations. These precision medicine-based approaches, which can be first applied to well-defined monogenic diseases such as FXS, can also serve to define drug responder profiles based on specific biomarkers or phenotypic features that can associate patients with different genetic backgrounds to a same candidate drug, thus repositioning a same drug for a larger number of patients with NDDs.
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Affiliation(s)
- Edgard Verdura
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Laura Pérez-Cano
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Rubén Sabido-Vera
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain
| | - Emre Guney
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain.,Research Programme on Biomedical Informatics, Hospital del Mar Medical Research Institute (IMIM), Departament de Ciències Experimentals i de la Salut (DCEXS), Pompeu Fabra University (UPF), Barcelona, Spain
| | - Jean-Marc Hyvelin
- Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland
| | - Lynn Durham
- Discovery and Data Science (DDS) Unit, Sociedad Limitada (STALICLA SL), Barcelona, Spain.,Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland
| | - Baltazar Gomez-Mancilla
- Drug Development Unit (DDU), Société Anonyme (STALICLA SA), Geneva, Switzerland.,Department Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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Sabitha KR, Shetty AK, Upadhya D. Patient-derived iPSC modeling of rare neurodevelopmental disorders: Molecular pathophysiology and prospective therapies. Neurosci Biobehav Rev 2020; 121:201-219. [PMID: 33370574 DOI: 10.1016/j.neubiorev.2020.12.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022]
Abstract
The pathological alterations that manifest during the early embryonic development due to inherited and acquired factors trigger various neurodevelopmental disorders (NDDs). Besides major NDDs, there are several rare NDDs, exhibiting specific characteristics and varying levels of severity triggered due to genetic and epigenetic anomalies. The rarity of subjects, paucity of neural tissues for detailed analysis, and the unavailability of disease-specific animal models have hampered detailed comprehension of rare NDDs, imposing heightened challenge to the medical and scientific community until a decade ago. The generation of functional neurons and glia through directed differentiation protocols for patient-derived iPSCs, CRISPR/Cas9 technology, and 3D brain organoid models have provided an excellent opportunity and vibrant resource for decoding the etiology of brain development for rare NDDs caused due to monogenic as well as polygenic disorders. The present review identifies cellular and molecular phenotypes demonstrated from patient-derived iPSCs and possible therapeutic opportunities identified for these disorders. New insights to reinforce the existing knowledge of the pathophysiology of these disorders and prospective therapeutic applications are discussed.
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Affiliation(s)
- K R Sabitha
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA.
| | - Dinesh Upadhya
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
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11
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Montez ARH, Bizarra MDF, Graça SR. Evaluation of oral characteristics and oral health of individuals with fragile X syndrome and related guardians perceptions. SPECIAL CARE IN DENTISTRY 2020; 41:13-19. [PMID: 33105044 DOI: 10.1111/scd.12529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/05/2020] [Accepted: 09/29/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To relate the oral health of individuals with fragile X syndrome (FXS) with their oral characteristics, habits, and difficulties in terms of oral hygiene and the perception of oral health of the guardians. METHODS AND RESULTS This observational transversal study included 31 volunteers who belong to the Portuguese Fragile X Syndrome Association. A questionnaire was presented to guardians, and a head and neck and oral examination was performed to the individuals: decay, missing and filled teeth index (DMFT) = 4.65, gingival index (GI) = 1.01, and simplified oral hygiene index (OHI-S) = 2.26 and Malocclusion Class Angle II (61.3%) with dental aesthetic index 34.90. A high-arch narrow palate (71%), accentuated gagging reflex (45.2%), and bruxism (22.6%) were the most common oral characteristics. There was a negative correlation between the several behaviors, attitudes, and habits reported by the guardians and all the indexes of oral health, with significance to the DMFT (P = .032), missing teeth (P = .032), and GI (P = .04). CONCLUSION There was a variability in oral characteristics, and these can represent a difficulty in performing oral hygiene. The collected data provide information for the health professionals and guardians to guide the monitoring of patients with FXS as well as to create strategies to improve oral hygiene.
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12
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Salcedo-Arellano MJ, Dufour B, McLennan Y, Martinez-Cerdeno V, Hagerman R. Fragile X syndrome and associated disorders: Clinical aspects and pathology. Neurobiol Dis 2020; 136:104740. [PMID: 31927143 PMCID: PMC7027994 DOI: 10.1016/j.nbd.2020.104740] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/17/2019] [Accepted: 01/08/2020] [Indexed: 12/23/2022] Open
Abstract
This review aims to assemble many years of research and clinical experience in the fields of neurodevelopment and neuroscience to present an up-to-date understanding of the clinical presentation, molecular and brain pathology associated with Fragile X syndrome, a neurodevelopmental condition that develops with the full mutation of the FMR1 gene, located in the q27.3 loci of the X chromosome, and Fragile X-associated tremor/ataxia syndrome a neurodegenerative disease experienced by aging premutation carriers of the FMR1 gene. It is important to understand that these two syndromes have a very distinct clinical and pathological presentation while sharing the same origin: the mutation of the FMR1 gene; revealing the complexity of expansion genetics.
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Affiliation(s)
- Maria Jimena Salcedo-Arellano
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA.
| | - Brett Dufour
- Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Yingratana McLennan
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA
| | - Veronica Martinez-Cerdeno
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA, USA; Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA, USA
| | - Randi Hagerman
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA, USA; Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, Sacramento, CA, USA.
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Pereverzeva DS, Tyushkevich SA, Gorbachevskaya NL, Mamokhina UA, Danilina KK. Heterogeneity of clinical characteristics of FMR1-related disorders. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:103-111. [DOI: 10.17116/jnevro2019119071103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Lubala TK, Lumaka A, Kanteng G, Mutesa L, Mukuku O, Wembonyama S, Hagerman R, Luboya ON, Lukusa Tshilobo P. Fragile X checklists: A meta-analysis and development of a simplified universal clinical checklist. Mol Genet Genomic Med 2018; 6:526-532. [PMID: 29624914 PMCID: PMC6081230 DOI: 10.1002/mgg3.398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 03/06/2018] [Accepted: 03/06/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Clinical checklists available have been developed to assess the risk of a positive Fragile X syndrome but they include relatively small sample sizes. Therefore, we carried out a meta-analysis that included statistical pooling of study results to obtain accurate figures on the prevalence of clinical predictors of Fragile X syndrome among patients with intellectual disability, thereby helping health professionals to improve their referrals for Fragile X testing. METHODS All published studies consisting of cytogenetic and/or molecular screening for fragile X syndrome among patients with intellectual disability, were eligible for the meta-analysis. All patients enrolled in clinical checklists trials of Fragile X syndrome were eligible for this review, with no exclusion based on ethnicity or age. Odds ratio values, with 95% confidence intervals as well as Cronbach coefficient alpha, was reported to assess the frequency of clinical characteristics in subjects with intellectual disability with and without the fragile X mutation to determine the most discriminating. RESULTS The following features were strongly associated with Fragile X syndrome: skin soft and velvety on the palms with redundancy of skin on the dorsum of hand [OR: 16.85 (95% CI 10.4-27.3; α:0.97)], large testes [OR: 7.14 (95% CI 5.53-9.22; α: 0.80)], large and prominent ears [OR: 18.62 (95% CI 14.38-24.1; α: 0.98)], pale blue eyes [OR: 8.97 (95% CI 4.75-16.97; α: 0.83)], family history of intellectual disability [OR: 3.43 (95% CI 2.76-4.27; α: 0.81)] as well as autistic-like behavior [OR: 3.08 (95% CI 2.48-3.83; α: 0.77)], Flat feet [OR: 11.53 (95% CI 6.79-19.56; α:0.91)], plantar crease [OR: 3.74 (95% CI 2.67-5.24; α: 0.70)]. We noted a weaker positive association between transverse palmar crease [OR: 2.68 (95% CI 1.70-4.18; α: 0.51)], elongated face [OR: 3.69 (95% CI 2.84-4.81; α: 0.63)]; hyperextensible metacarpo-phalangeal joints [OR: 2.68 (95% CI 2.15-3.34; α: 0.57)] and the Fragile X syndrome. CONCLUSION This study has identified the highest risk features for patients with Fragile X syndrome that have been used to design a universal clinical checklist.
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Affiliation(s)
- Toni Kasole Lubala
- Division of Dysmorphology & Birth DefectsDepartment of PediatricsUniversity of LubumbashiLubumbashiCongo
| | - Aimé Lumaka
- Faculté de MédecineDépartement de PédiatrieUniversité de KinshasaKinshasaCongo
- Centre de Génétique HumaineInstitut National de Recherche BiomédicaleKinshasaCongo
| | - Gray Kanteng
- Division of Dysmorphology & Birth DefectsDepartment of PediatricsUniversity of LubumbashiLubumbashiCongo
| | - Léon Mutesa
- Center for Human GeneticsSchool of Medicine and PharmacyCollege of Medicine and Health SciencesUniversity of RwandaKigaliRwanda
| | - Olivier Mukuku
- Département de PédiatrieInstitut Supérieur des Techniques MédicalesLubumbashiCongo
| | - Stanislas Wembonyama
- Division of Dysmorphology & Birth DefectsDepartment of PediatricsUniversity of LubumbashiLubumbashiCongo
| | - Randi Hagerman
- MIND InstituteUniversity of California DavisSacramentoCAUSA
- Department of PediatricsUniversity of California Davis Medical CenterSacramentoCAUSA
| | - Oscar Numbi Luboya
- Division of Dysmorphology & Birth DefectsDepartment of PediatricsUniversity of LubumbashiLubumbashiCongo
| | - Prosper Lukusa Tshilobo
- Faculté de MédecineDépartement de PédiatrieUniversité de KinshasaKinshasaCongo
- Centre de Génétique HumaineInstitut National de Recherche BiomédicaleKinshasaCongo
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