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Xie L, Li H, Xiao M, Chen N, Zang X, Liu Y, Ye H, Tang C. Epigenetic insights into Fragile X Syndrome. Front Cell Dev Biol 2024; 12:1432444. [PMID: 39220684 PMCID: PMC11362040 DOI: 10.3389/fcell.2024.1432444] [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: 05/14/2024] [Accepted: 08/05/2024] [Indexed: 09/04/2024] Open
Abstract
Fragile X Syndrome (FXS) is a genetic neurodevelopmental disorder closely associated with intellectual disability and autism spectrum disorders. The core of the disease lies in the abnormal expansion of the CGG trinucleotide repeat sequence at the 5'end of the FMR1 gene. When the repetition exceeds 200 times, it causes the silencing of the FMR1 gene, leading to the absence of the encoded Fragile X mental retardation protein 1 (FMRP). Although the detailed mechanism by which the CGG repeat expansion triggers gene silencing is yet to be fully elucidated, it is known that this process does not alter the promoter region or the coding sequence of the FMR1 gene. This discovery provides a scientific basis for the potential reversal of FMR1 gene silencing through interventional approaches, thereby improving the symptoms of FXS. Epigenetics, a mechanism of genetic regulation that does not depend on changes in the DNA sequence, has become a new focus in FXS research by modulating gene expression in a reversible manner. The latest progress in molecular genetics has revealed that epigenetics plays a key role in the pathogenesis and pathophysiological processes of FXS. This article compiles the existing research findings on the role of epigenetics in Fragile X Syndrome (FXS) with the aim of deepening the understanding of the pathogenesis of FXS to identify potential targets for new therapeutic strategies.
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Affiliation(s)
- Liangqun Xie
- The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - Huiying Li
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - MengLiang Xiao
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - Ningjing Chen
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - Xiaoxiao Zang
- The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Yingying Liu
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - Hong Ye
- Department of Obstetrics and Gynecology, The First College of Clinical Medical Science, Yichang Central People’s Hospital, Three Gorges University, Yichang, Hubei, China
| | - Chaogang Tang
- The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
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Luque MA, Morcuende S, Torres B, Herrero L. Kv7/M channel dysfunction produces hyperexcitability in hippocampal CA1 pyramidal cells of Fmr1 knockout mice. J Physiol 2024; 602:3769-3791. [PMID: 38976504 DOI: 10.1113/jp285244] [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: 07/04/2023] [Accepted: 06/18/2024] [Indexed: 07/10/2024] Open
Abstract
Fragile X syndrome (FXS), the most frequent monogenic form of intellectual disability, is caused by transcriptional silencing of the FMR1 gene that could render neuronal hyperexcitability. Here we show that pyramidal cells (PCs) in the dorsal CA1 region of the hippocampus elicited a larger action potential (AP) number in response to suprathreshold stimulation in juvenile Fmr1 knockout (KO) than wild-type (WT) mice. Because Kv7/M channels modulate CA1 PC excitability in rats, we investigated if their dysfunction produces neuronal hyperexcitability in Fmr1 KO mice. Immunohistochemical and western blot analyses showed no differences in the expression of Kv7.2 and Kv7.3 channel subunits between genotypes; however, the current mediated by Kv7/M channels was reduced in Fmr1 KO mice. In both genotypes, bath application of XE991 (10 μM), a blocker of Kv7/M channels: produced an increased AP number, produced an increased input resistance, produced a decreased AP voltage threshold and shaped AP medium afterhyperpolarization by increasing mean velocities. Retigabine (10 μM), an opener of Kv7/M channels, produced opposite effects to XE991. Both XE991 and retigabine abolished differences in all these parameters found in control conditions between genotypes. Furthermore, a low concentration of retigabine (2.5 μM) normalized CA1 PC excitability of Fmr1 KO mice. Finally, ex vivo seizure-like events evoked by 4-aminopyiridine (200 μM) in the dorsal CA1 region were more frequent in Fmr1 KO mice, and were abolished by retigabine (5-10 μM). We conclude that CA1 PCs of Fmr1 KO mice exhibit hyperexcitability, caused by Kv7/M channel dysfunction, and increased epileptiform activity, which were abolished by retigabine. KEY POINTS: Dorsal pyramidal cells of the hippocampal CA1 region of Fmr1 knockout mice exhibit hyperexcitability. Kv7/M channel activity, but not expression, is reduced in pyramidal cells of the hippocampal CA1 region of Fmr1 knockout mice. Kv7/M channel dysfunction causes hyperexcitability in pyramidal cells of the hippocampal CA1 region of Fmr1 knockout mice by increasing input resistance, decreasing AP voltage threshold and shaping medium afterhyperpolarization. A Kv7/M channel opener normalizes neuronal excitability in pyramidal cells of the hippocampal CA1 region of Fmr1 knockout mice. Ex vivo seizure-like events evoked in the dorsal CA1 region were more frequent in Fmr1 KO mice, and such an epileptiform activity was abolished by a Kv7/M channel opener depending on drug concentration. Kv7/M channels may represent a therapeutic target for treating symptoms associated with hippocampal alterations in fragile X syndrome.
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Affiliation(s)
- M Angeles Luque
- Departamento Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Sara Morcuende
- Departamento Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Blas Torres
- Departamento Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Luis Herrero
- Departamento Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
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Paprocka J, Coppola A, Cuccurullo C, Stawicka E, Striano P. Epilepsy, EEG and chromosomal rearrangements. Epilepsia Open 2024; 9:1192-1232. [PMID: 38837855 PMCID: PMC11296106 DOI: 10.1002/epi4.12951] [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: 08/16/2023] [Revised: 03/17/2024] [Accepted: 04/10/2024] [Indexed: 06/07/2024] Open
Abstract
Chromosomal abnormalities are associated with a broad spectrum of clinical manifestations, one of the more commonly observed of which is epilepsy. The frequency, severity, and type of epileptic seizures vary according to the macro- and microrearrangements present. Even within a single chromosomal anomaly, we most often deal with a phenotypic spectrum. The aim of the study was to look for chromosomal rearrangements with a characteristic electroencephalographic pattern. Only a few disorders have peculiar electroclinical abnormalities: 1p36, 4p16, 6q terminal or trisomy 12p, Angelman syndrome, inv dup 15, 15q13.3 deletions, ring 20, Down syndrome, or Xp11.22-11.23 duplication. We also reviewed studies on epileptic seizures and typical electroencephalographic patterns described in certain chromosomal rearrangements, focusing on the quest for potential electroclinical biomarkers. The comprehensive review concludes with clinical presentations of the most common micro and macro chromosomal rearrangements, such as 17q21.31 microdeletion, 6q terminal deletion, 15q inv dup syndrome, 2q24.4 deletion, Xp11.22-11.23 duplication, 15q13.3 microdeletion, 1p36 terminal deletion, 5q14.3 microdeletion, and Xq28 duplication. The papers reviewed did not identify any specific interictal electroencephalographic patterns that were unique and significant biomarkers for a given chromosomal microrearrangement. The types of seizures described varied, with both generalized and focal seizures of various morphologies being reported. Patients with chromosomal anomalies may also meet the criteria for specific epileptic syndromes such as Infantile Epilepsy Spasms Syndrome (IESS, West syndrome): 16p13.11, 15q13.3 and 17q21.31 microdeletions, 5q inv dup. syndrome; Dravet syndrome (2q24.4 deletion), Lennox-Gastaut syndrome (15q11 duplication. 1q13.3, 5q inv dup.); or Self-Limited Epilepsy with Autonomic Features (SeLEAS, Panayiotopoulos syndrome: terminal deletion of 6q.n), Self-Limited Epilepsy with Centrotemporal Spikes (SeLECT): fragile X syndrome. It is essential to better characterize groups of patients to more accurately define patterns of epilepsy and EEG abnormalities. This could lead to new treatment strategies. Future research is required to better understand epileptic syndromes and chromosomal rearrangements. PLAIN LANGUAGE SUMMARY: This paper presents EEG recording abnormalities in patients with various gene abnormalities that can cause epilepsy. The authors summarize these EEG variations based on a literature review to see if they occur frequently enough in other chromosomal abnormalities (in addition to those already known) to be a clue for further diagnosis.
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Affiliation(s)
- Justyna Paprocka
- Pediatric Neurology Department, Faculty of Medical SciencesMedical University of SilesiaKatowicePoland
| | - Antonietta Coppola
- Epilepsy Centre, Neurology Department of Neurology, Reproductive and OdontostomatologyFederico II UniversityNaplesItaly
| | - Claudia Cuccurullo
- Epilepsy Centre, Neurology Department of Neurology, Reproductive and OdontostomatologyFederico II UniversityNaplesItaly
| | - Elżbieta Stawicka
- Clinic of Paediatric NeurologyInstitute of Mother and ChildWarsawPoland
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthIRCCS Istituto Giannina GasliniGenoaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversity of GenoaGenoaItaly
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Protic D, Hagerman R. State-of-the-art therapies for fragile X syndrome. Dev Med Child Neurol 2024; 66:863-871. [PMID: 38385885 PMCID: PMC11144093 DOI: 10.1111/dmcn.15885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/23/2024]
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by a full mutation (> 200 CGG repeats) in the FMR1 gene. FXS is the leading cause of inherited intellectual disabilities and the most commonly known genetic cause of autism spectrum disorder. Children with FXS experience behavioral and sleep problems, anxiety, inattention, learning difficulties, and speech and language delays. There are no approved medications for FXS; however, there are several interventions and treatments aimed at managing the symptoms and improving the quality of life of individuals with FXS. A combination of non-pharmacological therapies and pharmacotherapy is currently the most effective treatment for FXS. Currently, several targeted treatments, such as metformin, sertraline, and cannabidiol, can be used by clinicians to treat FXS. Gene therapy is rapidly developing and holds potential as a prospective treatment option. Soon its efficacy and safety in patients with FXS will be demonstrated. WHAT THIS PAPER ADDS: Targeted treatment of fragile X syndrome (FXS) is the best current therapeutic approach. Gene therapy holds potential as a prospective treatment for FXS in the future.
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Affiliation(s)
- Dragana Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine University of Belgrade, Belgrade, Serbia
- Fragile X Clinic, Special Hospital for Cerebral Palsy and Developmental Neurology, Belgrade, Serbia
| | - Randi Hagerman
- Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, CA, USA
- Department of Pediatrics, University of California, Davis School of Medicine, Sacramento, CA, USA
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Tsotsokou G, Miliou A, Trompoukis G, Leontiadis LJ, Papatheodoropoulos C. Region-Related Differences in Short-Term Synaptic Plasticity and Synaptotagmin-7 in the Male and Female Hippocampus of a Rat Model of Fragile X Syndrome. Int J Mol Sci 2024; 25:6975. [PMID: 39000085 PMCID: PMC11240911 DOI: 10.3390/ijms25136975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/22/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Fragile X syndrome (FXS) is an intellectual developmental disorder characterized, inter alia, by deficits in the short-term processing of neural information, such as sensory processing and working memory. The primary cause of FXS is the loss of fragile X messenger ribonucleoprotein (FMRP), which is profoundly involved in synaptic function and plasticity. Short-term synaptic plasticity (STSP) may play important roles in functions that are affected by FXS. Recent evidence points to the crucial involvement of the presynaptic calcium sensor synaptotagmin-7 (Syt-7) in STSP. However, how the loss of FMRP affects STSP and Syt-7 have been insufficiently studied. Furthermore, males and females are affected differently by FXS, but the underlying mechanisms remain elusive. The aim of the present study was to investigate possible changes in STSP and the expression of Syt-7 in the dorsal (DH) and ventral (VH) hippocampus of adult males and females in a Fmr1-knockout (KO) rat model of FXS. We found that the paired-pulse ratio (PPR) and frequency facilitation/depression (FF/D), two forms of STSP, as well as the expression of Syt-7, are normal in adult KO males, but the PPR is increased in the ventral hippocampus of KO females (6.4 ± 3.7 vs. 18.3 ± 4.2 at 25 ms in wild type (WT) and KO, respectively). Furthermore, we found no gender-related differences, but did find robust region-dependent difference in the STSP (e.g., the PPR at 50 ms: 50.0 ± 5.5 vs. 17.6 ± 2.9 in DH and VH of WT male rats; 53.1 ± 3.6 vs. 19.3 ± 4.6 in DH and VH of WT female rats; 48.1 ± 2.3 vs. 19.1 ± 3.3 in DH and VH of KO male rats; and 51.2 ± 3.3 vs. 24.7 ± 4.3 in DH and VH of KO female rats). AMPA receptors are similarly expressed in the two hippocampal segments of the two genotypes and in both genders. Also, basal excitatory synaptic transmission is higher in males compared to females. Interestingly, we found more than a twofold higher level of Syt-7, not synaptotagmin-1, in the dorsal compared to the ventral hippocampus in the males of both genotypes (0.43 ± 0.1 vs. 0.16 ± 0.02 in DH and VH of WT male rats, and 0.6 ± 0.13 vs. 0.23 ± 0.04 in DH and VH of KO male rats) and in the WT females (0.97 ± 0.23 vs. 0.31 ± 0.09 in DH and VH). These results point to the susceptibility of the female ventral hippocampus to FMRP loss. Importantly, the different levels of Syt-7, which parallel the higher score of the dorsal vs. ventral hippocampus on synaptic facilitation, suggest that Syt-7 may play a pivotal role in defining the striking differences in STSP along the long axis of the hippocampus.
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Affiliation(s)
| | | | | | | | - Costas Papatheodoropoulos
- Lab of Physiology-Neurophysiology, Department of Medicine, University of Patras, 265 04 Patras, Greece; (G.T.); (A.M.); (G.T.); (L.J.L.)
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Sandoval SO, Méndez-Albelo NM, Xu Z, Zhao X. From wings to whiskers to stem cells: why every model matters in fragile X syndrome research. J Neurodev Disord 2024; 16:30. [PMID: 38872088 PMCID: PMC11177515 DOI: 10.1186/s11689-024-09545-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 05/21/2024] [Indexed: 06/15/2024] Open
Abstract
Fragile X syndrome (FXS) is caused by epigenetic silencing of the X-linked fragile X messenger ribonucleoprotein 1 (FMR1) gene located on chromosome Xq27.3, which leads to the loss of its protein product, fragile X messenger ribonucleoprotein (FMRP). It is the most prevalent inherited form of intellectual disability and the highest single genetic cause of autism. Since the discovery of the genetic basis of FXS, extensive studies using animal models and human pluripotent stem cells have unveiled the functions of FMRP and mechanisms underlying FXS. However, clinical trials have not yielded successful treatment. Here we review what we have learned from commonly used models for FXS, potential limitations of these models, and recommendations for future steps.
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Affiliation(s)
- Soraya O Sandoval
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Natasha M Méndez-Albelo
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Molecular Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Zhiyan Xu
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Graduate Program in Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA.
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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Johnson K, Stanfield AC, Scerif G, McKechanie A, Clarke A, Herring J, Smith K, Crawford H. A holistic approach to fragile X syndrome integrated guidance for person-centred care. JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES 2024; 37:e13214. [PMID: 38383947 DOI: 10.1111/jar.13214] [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: 04/28/2023] [Revised: 01/31/2024] [Accepted: 02/01/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND The Fragile X community has expressed a desire for centralised, national guidelines in the form of integrated guidance for Fragile X Syndrome (FXS). METHODS This article draws on existing literature reviews, primary research and clinical trials on FXS, a Fragile X Society conference workshop and first-hand experience of clinicians who have worked with those living with FXS over many years. RESULTS The article scopes proposed integrated guidance over the life course, including appendices of symptoms, comorbidities and referral options for FXS and Fragile X Premutation Associated Conditions. CONCLUSION Integrated guidance would provide an authoritative source for doctors, health professionals, therapists, care workers, social workers, educators, employers, families and those living with FXS, so that a holistic, person-centred approach can be taken across the United Kingdom to garner the best outcomes for those with FXS.
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Affiliation(s)
- Kirsten Johnson
- The Fragile X Society, Great Dunmow, Essex, UK
- Fragile X International, Brussels, Belgium
| | - Andrew C Stanfield
- The Fragile X Society, Great Dunmow, Essex, UK
- The Patrick Wild Centre, The University of Edinburgh, Edinburgh, UK
| | - Gaia Scerif
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | | | - Angus Clarke
- The Fragile X Society, Great Dunmow, Essex, UK
- Institute of Cancer & Genetics, Cardiff University, Cardiff, UK
| | - Jonathan Herring
- The Fragile X Society, Great Dunmow, Essex, UK
- Law Faculty, University of Oxford, Oxford, UK
| | - Kayla Smith
- Mental Health and Wellbeing Unit, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Hayley Crawford
- The Fragile X Society, Great Dunmow, Essex, UK
- Mental Health and Wellbeing Unit, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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Kucińska A, Hawuła W, Rutkowska L, Wysocka U, Kępczyński Ł, Piotrowicz M, Chilarska T, Wieczorek-Cichecka N, Połatyńska K, Przysło Ł, Gach A. The Use of CGH Arrays for Identifying Copy Number Variations in Children with Autism Spectrum Disorder. Brain Sci 2024; 14:273. [PMID: 38539661 PMCID: PMC10968557 DOI: 10.3390/brainsci14030273] [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: 01/31/2024] [Revised: 03/01/2024] [Accepted: 03/11/2024] [Indexed: 06/14/2024] Open
Abstract
Autism spectrum disorders (ASDs) encompass a broad group of neurodevelopmental disorders with varied clinical symptoms, all being characterized by deficits in social communication and repetitive behavior. Although the etiology of ASD is heterogeneous, with many genes involved, a crucial role is believed to be played by copy number variants (CNVs). The present study examines the role of copy number variation in the development of isolated ASD, or ASD with additional clinical features, among a group of 180 patients ranging in age from two years and four months to 17 years and nine months. Samples were taken and subjected to array-based comparative genomic hybridization (aCGH), the gold standard in detecting gains or losses in the genome, using a 4 × 180 CytoSure Autism Research Array, with a resolution of around 75 kb. The results indicated the presence of nine pathogenic and six likely pathogenic imbalances, and 20 variants of uncertain significance (VUSs) among the group. Relevant variants were more prevalent in patients with ASD and additional clinical features. Twelve of the detected variants, four of which were probably pathogenic, would not have been identified using the routine 8 × 60 k microarray. These results confirm the value of microarrays in ASD diagnostics and highlight the need for dedicated tools.
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Affiliation(s)
- Agata Kucińska
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Wanda Hawuła
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Lena Rutkowska
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Urszula Wysocka
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Łukasz Kępczyński
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Małgorzata Piotrowicz
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Tatiana Chilarska
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Nina Wieczorek-Cichecka
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
| | - Katarzyna Połatyńska
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (K.P.); (Ł.P.)
| | - Łukasz Przysło
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (K.P.); (Ł.P.)
| | - Agnieszka Gach
- Department of Genetics, Polish Mother’s Memorial Hospital-Research Institute, 93-338 Lodz, Poland; (W.H.); (L.R.); (U.W.); (Ł.K.); (M.P.); (T.C.); (N.W.-C.); (A.G.)
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Saraf TS, Chen Y, Tyagi R, Canal CE. Altered brain serotonin 5-HT 1A receptor expression and function in juvenile Fmr1 knockout mice. Neuropharmacology 2024; 245:109774. [PMID: 37923121 PMCID: PMC11426339 DOI: 10.1016/j.neuropharm.2023.109774] [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: 07/09/2023] [Revised: 10/01/2023] [Accepted: 10/21/2023] [Indexed: 11/07/2023]
Abstract
There are no approved pharmacotherapies for fragile X syndrome (FXS), a rare neurodevelopmental disorder caused by a mutation in the FMR1 promoter region that leads to various symptoms, including intellectual disability and auditory hypersensitivity. The gene that encodes inhibitory serotonin 1A receptors (5-HT1ARs) is differentially expressed in embryonic brain tissue from individuals with FXS, and 5-HT1ARs are highly expressed in neural systems that are disordered in FXS, providing a rationale to focus on 5-HT1ARs as targets to treat symptoms of FXS. We examined agonist-labeled 5-HT1AR densities in male and female Fmr1 knockout mice and found no differences in whole-brain 5-HT1AR expression in adult control compared to Fmr1 knockout mice. However, juvenile Fmr1 knockout mice had lower whole-brain 5-HT1AR expression than age-matched controls. Consistent with these results, juvenile Fmr1 knockout mice showed reduced behavioral responses elicited by the 5-HT1AR agonist (R)-8-OH-DPAT, effects blocked by the selective 5-HT1AR antagonist, WAY-100635. Also, treatment with the selective 5-HT1AR agonist, NLX-112, dose-dependently prevented audiogenic seizures (AGS) in juvenile Fmr1 knockout mice, an effect reversed by WAY-100635. Suggestive of a potential role for 5-HT1ARs in regulating AGS, compared to males, female Fmr1 knockout mice had a lower prevalence of AGS and higher expression of antagonist-labeled 5-HT1ARs in the inferior colliculus and auditory cortex. These results provide preclinical support that 5-HT1AR agonists may be therapeutic for young individuals with FXS hypersensitive to auditory stimuli.
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Affiliation(s)
- Tanishka S Saraf
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA, 30341, USA
| | - Yiming Chen
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA, 30341, USA
| | - Richa Tyagi
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA, 30341, USA
| | - Clinton E Canal
- Mercer University, College of Pharmacy, Department of Pharmaceutical Sciences, 3001 Mercer University Drive, Atlanta, GA, 30341, USA.
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Kaufmann WE, Raspa M, Bann CM, Gable JM, Harris HK, Budimirovic DB, Lozano R. Latent Class Analysis Identifies Distinctive Behavioral Subtypes in Children with Fragile X Syndrome. J Autism Dev Disord 2024; 54:725-737. [PMID: 36441429 PMCID: PMC10258834 DOI: 10.1007/s10803-022-05821-7] [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] [Accepted: 11/07/2022] [Indexed: 11/29/2022]
Abstract
Fragile X syndrome (FXS) is characterized by variable neurobehavioral abnormalities, which leads to difficulties in developing and evaluating treatments and in determining accurate prognosis. We employed a pediatric cross-sectional sample (1,072 males, 338 females) from FORWARD, a clinic-based natural history study, to identify behavioral subtypes by latent class analysis. Input included co-occurring behavioral conditions, sleep and sensory problems, autistic behavior scales (SCQ, SRS-2), and the Aberrant Behavior Checklist revised for FXS (ABCFX). A 5-class solution yielded the most clinically meaningful, pharmacotherapy independent behavioral groups with distinctive SCQ, SRS-2, and ABCFX profiles, and adequate non-overlap (≥ 71%): "Mild" (31%), "Moderate without Social Impairment" (32%), "Moderate with Social Impairment" (7%), "Moderate with Disruptive Behavior" (20%), and "Severe" (9%). Our findings support FXS subtyping, for improving clinical management and therapeutic development.
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Affiliation(s)
- Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA.
| | - Melissa Raspa
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709, USA
| | - Carla M Bann
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709, USA
| | - Julia M Gable
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC, 27709, USA
| | - Holly K Harris
- Texas Children's Hospital, 8080 North Stadium Drive, Houston, TX, 77054, USA
| | | | - Reymundo Lozano
- Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY, 10029, USA
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11
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Leontiadis LJ, Trompoukis G, Tsotsokou G, Miliou A, Felemegkas P, Papatheodoropoulos C. Rescue of sharp wave-ripples and prevention of network hyperexcitability in the ventral but not the dorsal hippocampus of a rat model of fragile X syndrome. Front Cell Neurosci 2023; 17:1296235. [PMID: 38107412 PMCID: PMC10722241 DOI: 10.3389/fncel.2023.1296235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/06/2023] [Indexed: 12/19/2023] Open
Abstract
Fragile X syndrome (FXS) is a genetic neurodevelopmental disorder characterized by intellectual disability and is related to autism. FXS is caused by mutations of the fragile X messenger ribonucleoprotein 1 gene (Fmr1) and is associated with alterations in neuronal network excitability in several brain areas including hippocampus. The loss of fragile X protein affects brain oscillations, however, the effects of FXS on hippocampal sharp wave-ripples (SWRs), an endogenous hippocampal pattern contributing to memory consolidation have not been sufficiently clarified. In addition, it is still not known whether dorsal and ventral hippocampus are similarly affected by FXS. We used a Fmr1 knock-out (KO) rat model of FXS and electrophysiological recordings from the CA1 area of adult rat hippocampal slices to assess spontaneous and evoked neural activity. We find that SWRs and associated multiunit activity are affected in the dorsal but not the ventral KO hippocampus, while complex spike bursts remain normal in both segments of the KO hippocampus. Local network excitability increases in the dorsal KO hippocampus. Furthermore, specifically in the ventral hippocampus of KO rats we found an increased effectiveness of inhibition in suppressing excitation and an upregulation of α1GABAA receptor subtype. These changes in the ventral KO hippocampus are accompanied by a striking reduction in its susceptibility to induced epileptiform activity. We propose that the neuronal network specifically in the ventral segment of the hippocampus is reorganized in adult Fmr1-KO rats by means of balanced changes between excitability and inhibition to ensure normal generation of SWRs and preventing at the same time derailment of the neural activity toward hyperexcitability.
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12
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Leontiadis LJ, Trompoukis G, Felemegkas P, Tsotsokou G, Miliou A, Papatheodoropoulos C. Increased Inhibition May Contribute to Maintaining Normal Network Function in the Ventral Hippocampus of a Fmr1-Targeted Transgenic Rat Model of Fragile X Syndrome. Brain Sci 2023; 13:1598. [PMID: 38002556 PMCID: PMC10669536 DOI: 10.3390/brainsci13111598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
A common neurobiological mechanism in several neurodevelopmental disorders, including fragile X syndrome (FXS), is alterations in the balance between excitation and inhibition in the brain. It is thought that in the hippocampus, as in other brain regions, FXS is associated with increased excitability and reduced inhibition. However, it is still not known whether these changes apply to both the dorsal and ventral hippocampus, which appear to be differently involved in neurodegenerative disorders. Using a Fmr1 knock-out (KO) rat model of FXS, we found increased neuronal excitability in both the dorsal and ventral KO hippocampus and increased excitatory synaptic transmission in the dorsal hippocampus. Interestingly, synaptic inhibition is significantly increased in the ventral but not the dorsal KO hippocampus. Furthermore, the ventral KO hippocampus displays increased expression of the α1GABAA receptor subtype and a remarkably reduced rate of epileptiform discharges induced by magnesium-free medium. In contrast, the dorsal KO hippocampus displays an increased rate of epileptiform discharges and similar expression of α1GABAA receptors compared with the dorsal WT hippocampus. Blockade of α5GABAA receptors by L-655,708 did not affect epileptiform discharges in any genotype or hippocampal segment, and the expression of α5GABAA receptors did not differ between WT and KO hippocampus. These results suggest that the increased excitability of the dorsal KO hippocampus contributes to its heightened tendency to epileptiform discharges, while the increased phasic inhibition in the Fmr1-KO ventral hippocampus may represent a homeostatic mechanism that compensates for the increased excitability reducing its vulnerability to epileptic activity.
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Affiliation(s)
| | | | | | | | | | - Costas Papatheodoropoulos
- Laboratory of Neurophysiology, Department of Medicine, University of Patras, 26504 Rion, Greece; (L.J.L.); (G.T. (George Trompoukis)); (P.F.); (G.T. (Giota Tsotsokou)); (A.M.)
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13
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Tyagi R, Saraf TS, Canal CE. The Psychedelic N, N-Dipropyltryptamine Prevents Seizures in a Mouse Model of Fragile X Syndrome via a Mechanism that Appears Independent of Serotonin and Sigma1 Receptors. ACS Pharmacol Transl Sci 2023; 6:1480-1491. [PMID: 37854624 PMCID: PMC10580393 DOI: 10.1021/acsptsci.3c00137] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Indexed: 10/20/2023]
Abstract
The serotonergic psychedelic psilocybin shows efficacy in treating neuropsychiatric disorders, though the mechanism(s) underlying its therapeutic effects remain unclear. We show that a similar psychedelic tryptamine, N,N-dipropyltryptamine (DPT), completely prevents audiogenic seizures (AGS) in an Fmr1 knockout mouse model of fragile X syndrome at a 10 mg/kg dose but not at lower doses (3 or 5.6 mg/kg). Despite showing in vitro that DPT is a serotonin 5-HT2A, 5-HT1B, and 5-HT1A receptor agonist (with that rank order of functional potency, determined with TRUPATH Gα/βγ biosensors), pretreatment with selective inhibitors of 5-HT2A/2C, 5-HT1B, or 5-HT1A receptors did not block DPT's antiepileptic effects; a pan-serotonin receptor antagonist was also ineffective. Because 5-HT1A receptor activation blocks AGS in Fmr1 knockout mice, we performed a dose-response experiment to evaluate DPT's engagement of 5-HT1A receptors in vivo. DPT elicited 5-HT1A-dependent effects only at doses greater than 10 mg/kg, further supporting that DPT's antiepileptic effects were not 5-HT1A-mediated. We also observed that the selective sigma1 receptor antagonist, NE-100, did not impact DPT's antiepileptic effects, suggesting DPT engagement of sigma1 receptors was not a crucial mechanism. Separately, we observed that DPT and NE-100 at high doses caused convulsions on their own that were qualitatively distinct from AGS. In conclusion, DPT dose-dependently blocked AGS in Fmr1 knockout mice, but neither serotonin nor sigma1 receptor antagonists prevented this action. Thus, DPT might have neurotherapeutic effects independent of its serotonergic psychedelic properties. However, DPT also caused seizures at high doses, showing that DPT has complex dose-dependent in vivo polypharmacology.
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Affiliation(s)
- Richa Tyagi
- Department of Pharmaceutical
Sciences, College of Pharmacy, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, United States
| | - Tanishka S. Saraf
- Department of Pharmaceutical
Sciences, College of Pharmacy, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, United States
| | - Clinton E. Canal
- Department of Pharmaceutical
Sciences, College of Pharmacy, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, United States
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14
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Burger P, Colin F, Strehle A, Mazzucotelli T, Collot N, Coutelle R, Durand B, Bouman A, Landau Prat D, Kleefstra T, Parrend P, Piton A, Koolen DA, Mandel JL. GenIDA: an international participatory database to gain knowledge on health issues related to genetic forms of neurodevelopmental disorders. J Neural Transm (Vienna) 2023; 130:459-471. [PMID: 36436153 PMCID: PMC9702708 DOI: 10.1007/s00702-022-02569-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 11/15/2022] [Indexed: 11/28/2022]
Abstract
Intellectual disability with or without manifestations of autism and/or epilepsy affects 1-2% of the population, and it is estimated that more than 30-50% of these cases have a single genetic cause. More than 1000 genes and recurrent chromosomal abnormalities are involved in these genetic forms of neurodevelopmental disorders, which often remain insufficiently described in terms of clinical spectrum, associated medical problems, etc., due to their rarity and the often-limited number of patients' phenotypes reported. GenIDA is an international online participatory database that aims to better characterise the clinical manifestations and natural histories of these rare diseases. Clinical information is reported by parents of affected individuals using a structured questionnaire exploring physical parameters, cognitive and behavioural aspects, the presence or absence of neurological disorders or problems affecting major physiological functions, as well as autonomy and quality of life. This strengthens the implication in research of the concerned families. GenIDA aims to construct international cohorts of significant size of individuals affected by a given condition. As of July 2022, GenIDA counts some 1545 documented patient records from over 60 nationalities and collaborates with clinicians and researchers around the world who have access to the anonymized data collected to generate new, medically meaningful information to improve patient care. We present the GenIDA database here, together with an overview of the possibilities it offers to affected individuals, their families, and professionals in charge of the management of genetic forms of neurodevelopmental disorders. Finally, case studies of cohorts will illustrate the usefulness of GenIDA.
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Affiliation(s)
- Pauline Burger
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France.
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France.
- Université de Strasbourg, Strasbourg, France.
| | - Florent Colin
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
- INSERM UMR S1109, Tumor Biomechanics Lab, Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, Strasbourg, France
| | - Axelle Strehle
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Timothée Mazzucotelli
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Nicole Collot
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
| | - Romain Coutelle
- Service de Psychiatrie de l'enfant et de l'adolescent, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- INSERM U 1114, Clinique Psychiatrique, Strasbourg, France
| | - Benjamin Durand
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Arianne Bouman
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Daphna Landau Prat
- Division of Ophthalmology, The Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Sheba Talpiot Medical Leadership Program, Tel Hashomer, Israel
| | - Tjitske Kleefstra
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Centre of Excellence for Neuropsychiatry, Vincent Van Gogh Institute for Psychiatry, Venray, The Netherlands
| | - Pierre Parrend
- ICube Laboratory (Laboratoire Des Sciences de l'ingénieur, de l'informatique et de l'imagerie), UMR 7357, Université de Strasbourg, CNRS, Strasbourg, France
- EPITA, Strasbourg, France
| | - Amélie Piton
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
- Laboratoire de Diagnostic Génétique, IGMA, Hôpitaux Universitaire de Strasbourg, Strasbourg, France
- Institut Universitaire de France, Paris, France
| | - David A Koolen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jean-Louis Mandel
- Department of Neurogenetics and Translational Medicine, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U 1258, Illkirch, France
- Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France
- Université de Strasbourg, Strasbourg, France
- University of Strasgourg Institute for Advanced Studies (USIAS), University of Strasbourg, Strasbourg, France
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15
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Cencelli G, Pacini L, De Luca A, Messia I, Gentile A, Kang Y, Nobile V, Tabolacci E, Jin P, Farace MG, Bagni C. Age-Dependent Dysregulation of APP in Neuronal and Skin Cells from Fragile X Individuals. Cells 2023; 12:758. [PMID: 36899894 PMCID: PMC10000963 DOI: 10.3390/cells12050758] [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: 11/06/2022] [Revised: 01/02/2023] [Accepted: 01/06/2023] [Indexed: 03/04/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common form of monogenic intellectual disability and autism, caused by the absence of the functional fragile X messenger ribonucleoprotein 1 (FMRP). FXS features include increased and dysregulated protein synthesis, observed in both murine and human cells. Altered processing of the amyloid precursor protein (APP), consisting of an excess of soluble APPα (sAPPα), may contribute to this molecular phenotype in mice and human fibroblasts. Here we show an age-dependent dysregulation of APP processing in fibroblasts from FXS individuals, human neural precursor cells derived from induced pluripotent stem cells (iPSCs), and forebrain organoids. Moreover, FXS fibroblasts treated with a cell-permeable peptide that decreases the generation of sAPPα show restored levels of protein synthesis. Our findings suggest the possibility of using cell-based permeable peptides as a future therapeutic approach for FXS during a defined developmental window.
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Affiliation(s)
- Giulia Cencelli
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
- Institute of Neurosurgery, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Catholic University, 00168 Rome, Italy
| | - Laura Pacini
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
- Faculty of Medicine, UniCamillus, Saint Camillus International University of Health and Medical Sciences, 00131 Rome, Italy
| | - Anastasia De Luca
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Ilenia Messia
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Antonietta Gentile
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Roma, 00166 Rome, Italy
| | - Yunhee Kang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Veronica Nobile
- Institute of Genomic Medicine, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Catholic University, 00168 Rome, Italy
| | - Elisabetta Tabolacci
- Institute of Genomic Medicine, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Catholic University, 00168 Rome, Italy
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Maria Giulia Farace
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Claudia Bagni
- Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
- Department of Fundamental Neurosciences, Faculty of Biology and Medicine, University of Lausanne, 1005 Lausanne, Switzerland
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16
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Ranjan R, Jha S, Prajjwal P, Chaudhary A, Dudeja P, Vora N, Mateen MA, Yousuf MA, Chaudhary B. Neurological, Psychiatric, and Multisystemic Involvement of Fragile X Syndrome Along With Its Pathophysiology, Methods of Screening, and Current Treatment Modalities. Cureus 2023; 15:e35505. [PMID: 37007359 PMCID: PMC10050793 DOI: 10.7759/cureus.35505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2023] [Indexed: 03/01/2023] Open
Abstract
Fragile X syndrome (FXS) is a hereditary disease that predominantly leads to intellectual disability (ID) in boys. It is the second prominent cause of ID, which manifests as a result of the atypical development of the cytosine-guanine-guanine (CGG) region. This irregular extension of the CGG region gives rise to methylation and silencing of the fragile X mental retardation 1 (FMR1) gene, causing a loss of the fragile X mental retardation 1 protein (FMRP). This reduction or loss of FMRP is the main cause of ID. It has a multisystemic involvement showing neuropsychiatric features such as ID, speech and language delay, autism spectrum disorder, sensory hyperarousal, social anxiety, abnormal eye contact, shyness, and aggressive behaviour. It is also known to cause musculoskeletal symptoms, ocular symptoms, cardiac abnormalities, and gastrointestinal symptoms. The management is challenging, and there is no known cure for the disease; hence an early diagnosis of the condition is needed through prenatal screening offered to couples with familial history of ID before conception. The management rests on non-pharmacological modalities, including applied behaviour analysis, physical therapy, occupational therapy, speech-language therapy, and pharmacologic management through symptomatic treatment of comorbid behaviours and psychiatric problems and some forms of targeted therapy.
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17
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Trajković J, Makevic V, Pesic M, Pavković-Lučić S, Milojevic S, Cvjetkovic S, Hagerman R, Budimirovic DB, Protic D. Drosophila melanogaster as a Model to Study Fragile X-Associated Disorders. Genes (Basel) 2022; 14:genes14010087. [PMID: 36672829 PMCID: PMC9859539 DOI: 10.3390/genes14010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022] Open
Abstract
Fragile X syndrome (FXS) is a global neurodevelopmental disorder caused by the expansion of CGG trinucleotide repeats (≥200) in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene. FXS is the hallmark of Fragile X-associated disorders (FXD) and the most common monogenic cause of inherited intellectual disability and autism spectrum disorder. There are several animal models used to study FXS. In the FXS model of Drosophila, the only ortholog of FMR1, dfmr1, is mutated so that its protein is missing. This model has several relevant phenotypes, including defects in the circadian output pathway, sleep problems, memory deficits in the conditioned courtship and olfactory conditioning paradigms, deficits in social interaction, and deficits in neuronal development. In addition to FXS, a model of another FXD, Fragile X-associated tremor/ataxia syndrome (FXTAS), has also been established in Drosophila. This review summarizes many years of research on FXD in Drosophila models.
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Affiliation(s)
- Jelena Trajković
- Faculty of Biology, University of Belgrade, 11000 Belgrade, Serbia
| | - Vedrana Makevic
- Department of Pathophysiology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Milica Pesic
- Institute of Human Genetics, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | | | - Sara Milojevic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Smiljana Cvjetkovic
- Department of Humanities, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Randi Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry, Fragile X Clinic, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Psychiatry & Behavioral Sciences-Child Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Dragana Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Correspondence:
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18
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Saraf TS, McGlynn RP, Bhatavdekar OM, Booth RG, Canal CE. FPT, a 2-Aminotetralin, Is a Potent Serotonin 5-HT 1A, 5-HT 1B, and 5-HT 1D Receptor Agonist That Modulates Cortical Electroencephalogram Activity in Adult Fmr1 Knockout Mice. ACS Chem Neurosci 2022; 13:3629-3640. [PMID: 36473166 PMCID: PMC10364582 DOI: 10.1021/acschemneuro.2c00574] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There are no approved medicines for fragile X syndrome (FXS), a monogenic, neurodevelopmental disorder. Electroencephalogram (EEG) studies show alterations in resting-state cortical EEG spectra, such as increased gamma-band power, in patients with FXS that are also observed in Fmr1 knockout models of FXS, offering putative biomarkers for drug discovery. Genes encoding serotonin receptors (5-HTRs), including 5-HT1A, 5-HT1B, and 5-HT1DRs, are differentially expressed in FXS, providing a rationale for investigating them as pharmacotherapeutic targets. Previously we reported pharmacological activity and preclinical neurotherapeutic effects in Fmr1 knockout mice of an orally active 2-aminotetralin, (S)-5-(2'-fluorophenyl)-N,N-dimethyl-1,2,3,4-tetrahydronaphthalen-2-amine (FPT). FPT is a potent (low nM), high-efficacy partial agonist at 5-HT1ARs and a potent, low-efficacy partial agonist at 5-HT7Rs. Here we report new observations that FPT also has potent and efficacious agonist activity at human 5-HT1B and 5-HT1DRs. FPT's Ki values at 5-HT1B and 5-HT1DRs were <5 nM, but it had nil activity (>10 μM Ki) at 5-HT1FRs. We tested the effects of FPT (5.6 mg/kg, subcutaneous) on EEG recorded above the somatosensory and auditory cortices in freely moving, adult Fmr1 knockout and control mice. Consistent with previous reports, we observed significantly increased relative gamma power in untreated or vehicle-treated male and female Fmr1 knockout mice from recordings above the left somatosensory cortex (LSSC). In addition, we observed sex effects on EEG power. FPT did not eliminate the genotype difference in relative gamma power from the LSSC. FPT, however, robustly decreased relative alpha power in the LSSC and auditory cortex, with more pronounced effects in Fmr1 KO mice. Similarly, FPT decreased relative alpha power in the right SSC but only in Fmr1 knockout mice. FPT also increased relative delta power, with more pronounced effects in Fmr1 KO mice and caused small but significant increases in relative beta power. Distinct impacts of FPT on cortical EEG were like effects caused by certain FDA-approved psychotropic medications (including baclofen, allopregnanolone, and clozapine). These results advance the understanding of FPT's pharmacological and neurophysiological effects.
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Affiliation(s)
- Tanishka S Saraf
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, United States
| | - Ryan P McGlynn
- Center for Drug Discovery, Department of Pharmaceutical Sciences, and Department of Chemistry and Chemical Biology, Northeastern University, 300 Huntington Street, Boston, Massachusetts 02115, United States
| | - Omkar M Bhatavdekar
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Croft Hall B27, Baltimore, Maryland 21218, United States
| | - Raymond G Booth
- Center for Drug Discovery, Department of Pharmaceutical Sciences, and Department of Chemistry and Chemical Biology, Northeastern University, 300 Huntington Street, Boston, Massachusetts 02115, United States
| | - Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, United States
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19
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Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives. Biomedicines 2022; 10:biomedicines10112934. [PMID: 36428502 PMCID: PMC9687921 DOI: 10.3390/biomedicines10112934] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.
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Berry-Kravis E. Disease-Targeted Treatment Translation in Fragile X Syndrome as a Model for Neurodevelopmental Disorders. J Child Neurol 2022; 37:797-812. [PMID: 35791522 DOI: 10.1177/08830738221089740] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Fragile X syndrome (FXS), the most common monogenic cause of intellectual disability and autism spectrum disorder, has been one of the first neurodevelopmental disorders in which molecular and neuronal mechanisms of disease were identified, leading to the concept of targeting the underlying disease to reverse symptoms. Translating findings in basic science and animal models to humans with FXS has proven difficult. These challenges have prompted the FXS field to organize to build interlocking projects and initiatives to improve consistency of supportive care, make clinical research accessible to families, generate collaborative research on natural history, outcome measures and biomarkers, and create clinical trial consortia and novel trial designs. This work has resulted in improved success in recent clinical trials, providing key steps toward regulatory approval of disease-targeted treatments for FXS. Progress in the FXS field has informed translation of transformative new disease-targeted therapies for other monogenic neurodevelopmental disorders.
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Affiliation(s)
- Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL, USA
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Chakraborty S, Parayil R, Mishra S, Nongthomba U, Clement JP. Epilepsy Characteristics in Neurodevelopmental Disorders: Research from Patient Cohorts and Animal Models Focusing on Autism Spectrum Disorder. Int J Mol Sci 2022; 23:ijms231810807. [PMID: 36142719 PMCID: PMC9501968 DOI: 10.3390/ijms231810807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Epilepsy, a heterogeneous group of brain-related diseases, has continued to significantly burden society and families. Epilepsy comorbid with neurodevelopmental disorders (NDDs) is believed to occur due to multifaceted pathophysiological mechanisms involving disruptions in the excitation and inhibition (E/I) balance impeding widespread functional neuronal circuitry. Although the field has received much attention from the scientific community recently, the research has not yet translated into actionable therapeutics to completely cure epilepsy, particularly those comorbid with NDDs. In this review, we sought to elucidate the basic causes underlying epilepsy as well as those contributing to the association of epilepsy with NDDs. Comprehensive emphasis is put on some key neurodevelopmental genes implicated in epilepsy, such as MeCP2, SYNGAP1, FMR1, SHANK1-3 and TSC1, along with a few others, and the main electrophysiological and behavioral deficits are highlighted. For these genes, the progress made in developing appropriate and valid rodent models to accelerate basic research is also detailed. Further, we discuss the recent development in the therapeutic management of epilepsy and provide a briefing on the challenges and caveats in identifying and testing species-specific epilepsy models.
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Affiliation(s)
- Sukanya Chakraborty
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Rrejusha Parayil
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Shefali Mishra
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - James P. Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
- Correspondence: ; Tel.: +91-08-2208-2613
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Neklyudova A, Smirnov K, Rebreikina A, Martynova O, Sysoeva O. Electrophysiological and Behavioral Evidence for Hyper- and Hyposensitivity in Rare Genetic Syndromes Associated with Autism. Genes (Basel) 2022; 13:671. [PMID: 35456477 PMCID: PMC9027402 DOI: 10.3390/genes13040671] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/29/2022] [Accepted: 04/05/2022] [Indexed: 01/27/2023] Open
Abstract
Our study reviewed abnormalities in spontaneous, as well as event-related, brain activity in syndromes with a known genetic underpinning that are associated with autistic symptomatology. Based on behavioral and neurophysiological evidence, we tentatively subdivided the syndromes on primarily hyper-sensitive (Fragile X, Angelman) and hypo-sensitive (Phelan-McDermid, Rett, Tuberous Sclerosis, Neurofibromatosis 1), pointing to the way of segregation of heterogeneous idiopathic ASD, that includes both hyper-sensitive and hypo-sensitive individuals. This segmentation links abnormalities in different genes, such as FMR1, UBE3A, GABRB3, GABRA5, GABRG3, SHANK3, MECP2, TSC1, TSC2, and NF1, that are causative to the above-mentioned syndromes and associated with synaptic transmission and cell growth, as well as with translational and transcriptional regulation and with sensory sensitivity. Excitation/inhibition imbalance related to GABAergic signaling, and the interplay of tonic and phasic inhibition in different brain regions might underlie this relationship. However, more research is needed. As most genetic syndromes are very rare, future investigations in this field will benefit from multi-site collaboration with a common protocol for electrophysiological and event-related potential (EEG/ERP) research that should include an investigation into all modalities and stages of sensory processing, as well as potential biomarkers of GABAergic signaling (such as 40-Hz ASSR).
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Affiliation(s)
- Anastasia Neklyudova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, 117485 Moscow, Russia; (A.N.); (K.S.); (A.R.); (O.M.)
| | - Kirill Smirnov
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, 117485 Moscow, Russia; (A.N.); (K.S.); (A.R.); (O.M.)
| | - Anna Rebreikina
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, 117485 Moscow, Russia; (A.N.); (K.S.); (A.R.); (O.M.)
- Sirius Center for Cognitive Research, Sirius University of Science and Technology, 354340 Sochi, Russia
| | - Olga Martynova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, 117485 Moscow, Russia; (A.N.); (K.S.); (A.R.); (O.M.)
| | - Olga Sysoeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, 117485 Moscow, Russia; (A.N.); (K.S.); (A.R.); (O.M.)
- Sirius Center for Cognitive Research, Sirius University of Science and Technology, 354340 Sochi, Russia
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Protic DD, Aishworiya R, Salcedo-Arellano MJ, Tang SJ, Milisavljevic J, Mitrovic F, Hagerman RJ, Budimirovic DB. Fragile X Syndrome: From Molecular Aspect to Clinical Treatment. Int J Mol Sci 2022; 23:1935. [PMID: 35216055 PMCID: PMC8875233 DOI: 10.3390/ijms23041935] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 02/01/2023] Open
Abstract
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by the full mutation as well as highly localized methylation of the fragile X mental retardation 1 (FMR1) gene on the long arm of the X chromosome. Children with FXS are commonly co-diagnosed with Autism Spectrum Disorder, attention and learning problems, anxiety, aggressive behavior and sleep disorder, and early interventions have improved many behavior symptoms associated with FXS. In this review, we performed a literature search of original and review articles data of clinical trials and book chapters using MEDLINE (1990-2021) and ClinicalTrials.gov. While we have reviewed the biological importance of the fragile X mental retardation protein (FMRP), the FXS phenotype, and current diagnosis techniques, the emphasis of this review is on clinical interventions. Early non-pharmacological interventions in combination with pharmacotherapy and targeted treatments aiming to reverse dysregulated brain pathways are the mainstream of treatment in FXS. Overall, early diagnosis and interventions are fundamental to achieve optimal clinical outcomes in FXS.
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Affiliation(s)
- Dragana D. Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia
| | - Ramkumar Aishworiya
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Khoo Teck Puat-National University Children’s Medical Institute, National University Health System, 5 Lower Kent Ridge Road, Singapore 119074, Singapore
| | - Maria Jimena Salcedo-Arellano
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA 95817, USA
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Si Jie Tang
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
| | - Jelena Milisavljevic
- Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia; (J.M.); (F.M.)
| | - Filip Mitrovic
- Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia; (J.M.); (F.M.)
| | - Randi J. Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, 2825 50th Street, Sacramento, CA 95817, USA; (R.A.); (M.J.S.-A.); (S.J.T.); (R.J.H.)
- Department of Pediatrics, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry, Fragile X Clinic, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Psychiatry & Behavioral Sciences-Child Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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