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Jiraanont P, Zafarullah M, Sulaiman N, Espinal GM, Randol JL, Durbin-Johnson B, Schneider A, Hagerman RJ, Hagerman PJ, Tassone F. FMR1 Protein Expression Correlates with Intelligence Quotient in Both Peripheral Blood Mononuclear Cells and Fibroblasts from Individuals with an FMR1 Mutation. J Mol Diagn 2024; 26:498-509. [PMID: 38522837 DOI: 10.1016/j.jmoldx.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/15/2024] [Accepted: 02/23/2024] [Indexed: 03/26/2024] Open
Abstract
Fragile X syndrome (FXS) is the most common heritable form of intellectual disability and is caused by CGG repeat expansions exceeding 200 (full mutation). Such expansions lead to hypermethylation and transcriptional silencing of the fragile X messenger ribonucleoprotein 1 (FMR1) gene. As a consequence, little or no FMR1 protein (FMRP) is produced; absence of the protein, which normally is responsible for neuronal development and maintenance, causes the syndrome. Previous studies have demonstrated the causal relationship between FMRP levels and cognitive abilities in peripheral blood mononuclear cells (PBMCs) and dermal fibroblast cell lines of patients with FXS. However, it is arguable whether PBMCs or fibroblasts would be the preferred surrogate for measuring molecular markers, particularly FMRP, to represent the cognitive impairment, a core symptom of FXS. To address this concern, CGG repeats, methylation status, FMR1 mRNA, and FMRP levels were measured in both PBMCs and fibroblasts derived from 66 individuals. The findings indicated a strong association between FMR1 mRNA expression levels and CGG repeat numbers in PBMCs of premutation males after correcting for methylation status. Moreover, FMRP expression levels from both PBMCs and fibroblasts of male participants with a hypermethylated full mutation and with mosaicism demonstrated significant association between the intelligence quotient levels and FMRP levels, suggesting that PBMCs may be preferable for FXS clinical studies, because of their greater accessibility.
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Affiliation(s)
- Poonnada Jiraanont
- Division of Molecular and Cellular Medicine, Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Marwa Zafarullah
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California
| | - Noor Sulaiman
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California
| | - Glenda M Espinal
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California
| | - Jamie L Randol
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California
| | - Blythe Durbin-Johnson
- Division of Biostatistics, University of California, Davis, School of Medicine, Davis, California
| | - Andrea Schneider
- Department of Pediatrics, University of California, Davis, School of Medicine, Davis, California; UC Davis MIND Institute, University of California, Davis, Sacramento, California
| | - Randi J Hagerman
- Department of Pediatrics, University of California, Davis, School of Medicine, Davis, California; UC Davis MIND Institute, University of California, Davis, Sacramento, California
| | - Paul J Hagerman
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California; UC Davis MIND Institute, University of California, Davis, Sacramento, California
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Davis, California; UC Davis MIND Institute, University of California, Davis, Sacramento, California.
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2
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McKinney WS, Williford DN, Abbeduto L, Schmitt LM. The impact of social-environmental factors on IQ in syndromic intellectual developmental disabilities. J Clin Transl Sci 2024; 8:e59. [PMID: 38655457 PMCID: PMC11036438 DOI: 10.1017/cts.2024.510] [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: 12/21/2023] [Revised: 03/14/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
Despite having the same underlying genetic etiology, individuals with the same syndromic form of intellectual developmental disability (IDD) show a large degree of interindividual differences in cognition and IQ. Research indicates that up to 80% of the variation in IQ scores among individuals with syndromic IDDs is attributable to nongenetic effects, including social-environmental factors. In this narrative review, we summarize evidence of the influence that factors related to economic stability (focused on due to its prevalence in existing literature) have on IQ in individuals with syndromic IDDs. We also highlight the pathways through which economic stability is hypothesized to impact cognitive development and drive individual differences in IQ among individuals with syndromic IDDs. We also identify broader social-environmental factors (e.g., social determinants of health) that warrant consideration in future research, but that have not yet been explored in syndromic IDDs. We conclude by making recommendations to address the urgent need for further research into other salient factors associated with heterogeneity in IQ. These recommendations ultimately may shape individual- and community-level interventions and may inform systems-level public policy efforts to promote the cognitive development of and improve the lived experiences of individuals with syndromic IDDs.
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Affiliation(s)
- Walker S. McKinney
- Department of Behavioral Medicine and Clinical Psychology,
Cincinnati Children’s Hospital Medical Center,
Cincinnati, OH, USA
| | - Desireé N. Williford
- Department of Behavioral Medicine and Clinical Psychology,
Cincinnati Children’s Hospital Medical Center,
Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of
Medicine, Cincinnati, OH, USA
| | - Leonard Abbeduto
- MIND Institute, University of California Davis,
Sacramento, CA, USA
- Department of Psychiatry and Behavioral Sciences, University
of California Davis, Sacramento, CA,
USA
| | - Lauren M. Schmitt
- Department of Behavioral Medicine and Clinical Psychology,
Cincinnati Children’s Hospital Medical Center,
Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of
Medicine, Cincinnati, OH, USA
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3
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Randol JL, Kim K, Ponzini MD, Tassone F, Falcon AK, Hagerman RJ, Hagerman PJ. Variation of FMRP Expression in Peripheral Blood Mononuclear Cells from Individuals with Fragile X Syndrome. Genes (Basel) 2024; 15:356. [PMID: 38540415 PMCID: PMC10969917 DOI: 10.3390/genes15030356] [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: 02/12/2024] [Revised: 03/02/2024] [Accepted: 03/08/2024] [Indexed: 04/07/2024] Open
Abstract
Fragile X syndrome (FXS) is the most common heritable cause of intellectual disability and autism spectrum disorder. The syndrome is often caused by greatly reduced or absent protein expression from the fragile X messenger ribonucleoprotein 1 (FMR1) gene due to expansion of a 5'-non-coding trinucleotide (CGG) element beyond 200 repeats (full mutation). To better understand the complex relationships among FMR1 allelotype, methylation status, mRNA expression, and FMR1 protein (FMRP) levels, FMRP was quantified in peripheral blood mononuclear cells for a large cohort of FXS (n = 154) and control (n = 139) individuals using time-resolved fluorescence resonance energy transfer. Considerable size and methylation mosaicism were observed among individuals with FXS, with FMRP detected only in the presence of such mosaicism. No sample with a minimum allele size greater than 273 CGG repeats had significant levels of FMRP. Additionally, an association was observed between FMR1 mRNA and FMRP levels in FXS samples, predominantly driven by those with the lowest FMRP values. This study underscores the complexity of FMR1 allelotypes and FMRP expression and prompts a reevaluation of FXS therapies aimed at reactivating large full mutation alleles that are likely not capable of producing sufficient FMRP to improve cognitive function.
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Affiliation(s)
- Jamie L. Randol
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Kyoungmi Kim
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, UC Davis Health, Sacramento, CA 95817, USA
- Department of Public Health Sciences, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Matthew D. Ponzini
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, UC Davis Health, Sacramento, CA 95817, USA
- Department of Public Health Sciences, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA 95616, USA
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, UC Davis Health, Sacramento, CA 95817, USA
| | - Alexandria K. Falcon
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Randi J. Hagerman
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, UC Davis Health, Sacramento, CA 95817, USA
- Department of Pediatrics, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Paul J. Hagerman
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Davis, CA 95616, USA
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute, UC Davis Health, Sacramento, CA 95817, USA
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4
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Ethridge LE, Pedapati EV, Schmitt LM, Norris JE, Auger E, De Stefano LA, Sweeney JA, Erickson CA. Validating brain activity measures as reliable indicators of individual diagnostic group and genetically mediated sub-group membership Fragile X Syndrome. RESEARCH SQUARE 2024:rs.3.rs-3849272. [PMID: 38313274 PMCID: PMC10836101 DOI: 10.21203/rs.3.rs-3849272/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Recent failures translating preclinical behavioral treatment effects to positive clinical trial results in humans with Fragile X Syndrome (FXS) support refocusing attention on biological pathways and associated measures, such as electroencephalography (EEG), with strong translational potential and small molecule target engagement. This study utilized guided machine learning to test promising translational EEG measures (resting power and auditory chirp oscillatory variables) in a large heterogeneous sample of individuals with FXS to identify best performing EEG variables for reliably separating individuals with FXS, and genetically-mediated subgroups within FXS, from typically developing controls. Best performing variables included resting relative frontal theta power, all combined whole-head resting power bands, posterior peak alpha frequency (PAF), combined PAF across all measured regions, combined theta, alpha, and gamma power during the chirp, and all combined chirp oscillatory variables. Sub-group analyses best discriminated non-mosaic FXS males via whole-head resting relative power (AUC = .9250), even with data reduced to a 20-channel clinical montage. FXS females were nearly perfectly discriminated by combined theta, alpha, and gamma power during the chirp (AUC = .9522). Results support use of resting and auditory oscillatory tasks to reliably identify neural deficit in FXS, and to identify specific translational targets for genetically-mediated sub-groups, supporting potential points for stratification.
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Rahmatullah N, Schmitt LM, De Stefano L, Post S, Robledo J, Chaudhari G, Pedapati E, Erickson C, Portera-Cailliau C, Goel A. Hypersensitivity to Distractors in Fragile X Syndrome from Loss of Modulation of Cortical VIP Interneurons. J Neurosci 2023; 43:8172-8188. [PMID: 37816596 PMCID: PMC10697397 DOI: 10.1523/jneurosci.0571-23.2023] [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: 03/29/2023] [Revised: 08/11/2023] [Accepted: 09/14/2023] [Indexed: 10/12/2023] Open
Abstract
Attention deficit is one of the most prominent and disabling symptoms in Fragile X syndrome (FXS). Hypersensitivity to sensory stimuli contributes to attention difficulties by overwhelming and/or distracting affected individuals, which disrupts activities of daily living at home and learning at school. We find that auditory or visual distractors selectively impair visual discrimination performance in humans and mice with FXS but not in typically developing controls. In both species, males and females were examined. Vasoactive intestinal polypeptide (VIP) neurons were significantly modulated by incorrect responses in the poststimulus period during early distractor trials in WT mice, consistent with their known role as error signals. Strikingly, however, VIP cells from Fmr1 -/- mice showed little modulation in error trials, and this correlated with their poor performance on the distractor task. Thus, VIP interneurons and their reduced modulatory influence on pyramidal cells could be a potential therapeutic target for attentional difficulties in FXS.SIGNIFICANCE STATEMENT Sensory hypersensitivity, impulsivity, and persistent inattention are among the most consistent clinical features of FXS, all of which impede daily functioning and create barriers to learning. However, the neural mechanisms underlying sensory over-reactivity remain elusive. To overcome a significant challenge in translational FXS research we demonstrate a compelling alignment of sensory over-reactivity in both humans with FXS and Fmr1 -/- mice (the principal animal model of FXS) using a novel analogous distractor task. Two-photon microscopy in mice revealed that lack of modulation by VIP cells contributes to susceptibility to distractors. Implementing research efforts we describe here can help identify dysfunctional neural mechanisms associated not only with sensory issues but broader impairments, including those in learning and cognition.
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Affiliation(s)
- Noorhan Rahmatullah
- Neuroscience Graduate Program, University of California, Riverside, Riverside, California 92521
- Department of Psychology, University of California, Riverside, Riverside, California 92521
| | - Lauren M Schmitt
- Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati OH 45267
| | - Lisa De Stefano
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnatti, Ohio 45267
| | - Sam Post
- Department of Psychology, University of California, Riverside, Riverside, California 92521
| | - Jessica Robledo
- Department of Psychology, University of California, Riverside, Riverside, California 92521
| | - Gunvant Chaudhari
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Ernest Pedapati
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnatti, Ohio 45267
- Department of Neurology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnatti, Ohio 45267
| | - Craig Erickson
- Department of Psychiatry, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnatti, Ohio 45267
| | - Carlos Portera-Cailliau
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Anubhuti Goel
- Neuroscience Graduate Program, University of California, Riverside, Riverside, California 92521
- Department of Psychology, University of California, Riverside, Riverside, California 92521
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6
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Mastrorosa FK, Miller DE, Eichler EE. Applications of long-read sequencing to Mendelian genetics. Genome Med 2023; 15:42. [PMID: 37316925 DOI: 10.1186/s13073-023-01194-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 05/18/2023] [Indexed: 06/16/2023] Open
Abstract
Advances in clinical genetic testing, including the introduction of exome sequencing, have uncovered the molecular etiology for many rare and previously unsolved genetic disorders, yet more than half of individuals with a suspected genetic disorder remain unsolved after complete clinical evaluation. A precise genetic diagnosis may guide clinical treatment plans, allow families to make informed care decisions, and permit individuals to participate in N-of-1 trials; thus, there is high interest in developing new tools and techniques to increase the solve rate. Long-read sequencing (LRS) is a promising technology for both increasing the solve rate and decreasing the amount of time required to make a precise genetic diagnosis. Here, we summarize current LRS technologies, give examples of how they have been used to evaluate complex genetic variation and identify missing variants, and discuss future clinical applications of LRS. As costs continue to decrease, LRS will find additional utility in the clinical space fundamentally changing how pathological variants are discovered and eventually acting as a single-data source that can be interrogated multiple times for clinical service.
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Affiliation(s)
| | - Danny E Miller
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, WA, 98195, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, 98195, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA.
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7
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Shieh M, Amkraut K, Spiridigliozzi GA, Adayev T, Nicholson K, McConkie‐Rosell A, McDonald M, Pennington M, Sebastian S, Lachiewicz AM. High performing male with fragile X syndrome with an unmethylated FMR1 full mutation: The relevance of clinical and genetic correlations. Clin Case Rep 2023; 11:e7371. [PMID: 37361657 PMCID: PMC10290186 DOI: 10.1002/ccr3.7371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 06/28/2023] Open
Abstract
A high performing male with an unmethylated full mutation in the fragile X messenger ribonucleoprotein 1 (FMR1) gene surpassed our expectations into young adulthood. Although initial genetic findings helped make a correct fragile X syndrome (FXS) determination, the report was insufficient. Ten years later, we repeated and conducted additional genetic and clinical studies to determine whether more information could assist with treatment and counseling. The genetic findings were very consistent with his high functioning and would have enabled us to be more confident about a good developmental outcome had they been available previously. As FXS enters the mainstream of well-understood genetic disorders and technological advancements improve genetic tests, it should be clearer to clinical providers what a full FXS assessment could include to provide high quality information for care. For individuals with FXS who are high functioning, their families and clinical professionals would benefit from knowing more genetic findings, including, most importantly, methylation status, but also the FMR1 protein (FMRP) level and mRNA level. While we now know that obtaining only the CGG repeat number is not always adequate to inform accurate clinical care, future studies are likely to show the benefit of studying other biomarkers, such as mRNA levels.
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Affiliation(s)
- Meg Shieh
- Department of ChemistryBrown UniversityProvidenceRhode IslandUSA
- Department of PediatricsDuke University Health SystemDurhamNorth CarolinaUSA
| | - Keren Amkraut
- Department of PediatricsDuke University Health SystemDurhamNorth CarolinaUSA
| | - Gail A. Spiridigliozzi
- Department of PediatricsDuke University Health SystemDurhamNorth CarolinaUSA
- Department of Psychiatry and Behavioral SciencesDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Tatyana Adayev
- Department of Human GeneticsNew York State Institute for Basic Research in Developmental DisabilitiesNew YorkNew YorkUSA
| | - Kaylea Nicholson
- Department of Communication SciencesDuke University Health CenterDurhamNorth CarolinaUSA
| | | | - Marie McDonald
- Department of PediatricsDuke University Health SystemDurhamNorth CarolinaUSA
| | | | - Siby Sebastian
- Department of PathologyDuke University Health SystemDurhamNorth CarolinaUSA
| | - Ave M. Lachiewicz
- Department of PediatricsDuke University Health SystemDurhamNorth CarolinaUSA
- Department of Psychiatry and Behavioral SciencesDuke University Medical CenterDurhamNorth CarolinaUSA
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8
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Schmitt LM, Will M, Shaffer R, Erickson C. A Paradigm Shifting View of Intellectual Disability: A Near Normal Distribution of IQ in Fragile X Syndrome. RESEARCH SQUARE 2023:rs.3.rs-2869313. [PMID: 37205401 PMCID: PMC10187411 DOI: 10.21203/rs.3.rs-2869313/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fragile X Syndrome (FXS) is an X-linked disorder leading to the loss of expression of FMR1-protein product, FMRP. The absence or deficiency of FMRP is thought to result in the characteristic FXS phenotypes, including intellectual disability. Identifying the relationship between FMRP levels and IQ may be critical to better understand underlying mechanisms and advance treatment development and planning. A sample of 80 individuals with FXS (67% male), aged 8-45 years, completed IQ testing and blood draw via venipuncture to determine the relationship between IQ scores and FMRP levels as well as the normalcy of IQ distributions. In females with FXS only, higher FMRP levels were associated with higher IQ. In contrast, males with FXS showed a downward shifted but otherwise normal distribution of IQ scores. Our findings offer a paradigm-shifting views of FXS-males with FXS have normally distributed IQ that is downshifted 5 standard deviations. Our novel work provides evidence of a "FXS standard curve", and is a critical step towards establishing molecular markers of disease severity in FXS. There is much future work to better understand the mechanism by which FMRP loss leads to intellectual disability and what biological/genetic and socio-environmental factors contribute to variation in IQ.
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9
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Straub D, Schmitt LM, Boggs AE, Horn PS, Dominick KC, Gross C, Erickson CA. A sensitive and reproducible qRT-PCR assay detects physiological relevant trace levels of FMR1 mRNA in individuals with Fragile X syndrome. Sci Rep 2023; 13:3808. [PMID: 36882476 PMCID: PMC9992378 DOI: 10.1038/s41598-023-29786-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/10/2023] [Indexed: 03/09/2023] Open
Abstract
Fragile X syndrome (FXS) is the most common inherited intellectual disability. FXS is caused by a trinucleotide repeat expansion in the 5' untranslated region of the FMR1 gene, which leads to gene methylation, transcriptional silencing, and lack of expression of Fragile X Messenger Riboprotein (FMRP). Currently available FXS therapies are inefficient, and the disease severity is highly variable, making it difficult to predict disease trajectory and treatment response. We and others have recently shown that a subset of full-mutation, fully-methylated (FM-FM) males with FXS express low amounts of FMRP which could contribute to phenotypic variability. To better understand the underlying mechanisms, we developed a sensitive qRT-PCR assay to detect FMR1 mRNA in blood. This assay reproducibly detects trace amounts of FMR1 mRNA in a subset of FM-FM males, suggesting that current Southern Blot and PCR determination of FM-FM status is not always associated with complete transcriptional silencing. The functional relevance of trace-level FMR1 mRNA is confirmed by showing a positive correlation with cognitive function; however, phenotypic variability is not fully explained by FMR1 expression. These results corroborate the need for better molecular assays for FXS diagnosis and encourage studies to elucidate the factors contributing to the phenotypic variability of FXS.
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Affiliation(s)
- Devan Straub
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
| | - Lauren M Schmitt
- Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
| | - Anna E Boggs
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
| | - Paul S Horn
- Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
- Division of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229-3039, USA
| | - Kelli C Dominick
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Stetson Building Suite 3200, 260 Stetson Street, Cincinnati, OH, 45267-0559, USA
| | - Christina Gross
- Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA
- Division of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229-3039, USA
| | - Craig A Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3039, USA.
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Stetson Building Suite 3200, 260 Stetson Street, Cincinnati, OH, 45267-0559, USA.
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10
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Rahmatullah N, Schmitt LM, De Stefano L, Post S, Robledo J, Chaudhari GR, Pedapati E, Erickson CA, Portera-Cailliau C, Goel A. Hypersensitivity to distractors in Fragile X syndrome from loss of modulation of cortical VIP interneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.03.522654. [PMID: 36711901 PMCID: PMC9881942 DOI: 10.1101/2023.01.03.522654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Attention deficit is one of the most prominent and disabling symptoms in Fragile X Syndrome (FXS). Hypersensitivity to sensory stimuli contributes to attention difficulties by overwhelming and/or distracting affected individuals, which disrupts activities of daily living at home and learning at school. We find that auditory or visual distractors selectively impair visual discrimination performance in both humans and mice with FXS, but not their typically developing controls. Vasoactive intestinal polypeptide (VIP) neurons were significantly modulated by incorrect responses in the post-stimulus period during early distractor trials in WT mice, consistent with their known role as 'error' signals. Strikingly, however, VIP cells from Fmr1-/- mice showed little modulation in error trials, and this correlated with their poor performance on the distractor task. Thus, VIP interneurons and their reduced modulatory influence on pyramidal cells, could be a potential therapeutic target for attentional difficulties in FXS.
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Affiliation(s)
- Noorhan Rahmatullah
- Neuroscience Graduate Program, UC Riverside, CA
- Department of Psychology, UC Riverside, CA
| | - Lauren M. Schmitt
- Department of Psychiatry, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, OH
| | - Lisa De Stefano
- Department of Psychiatry, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, OH
| | - Sam Post
- Department of Psychology, UC Riverside, CA
| | | | | | - Ernest Pedapati
- Department of Psychiatry, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, OH
- Department of Neurology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, OH
| | - Craig A. Erickson
- Department of Psychiatry, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, OH
| | - Carlos Portera-Cailliau
- Department of Neurology, David Geffen School of Medicine at UCLA, CA
- Department of Neurobiology, David Geffen School of Medicine at UCLA, CA
| | - Anubhuti Goel
- Neuroscience Graduate Program, UC Riverside, CA
- Department of Psychology, UC Riverside, CA
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11
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Schmitt LM, Li J, Liu R, Horn PS, Sweeney JA, Erickson CA, Pedapati EV. Altered frontal connectivity as a mechanism for executive function deficits in fragile X syndrome. Mol Autism 2022; 13:47. [PMID: 36494861 PMCID: PMC9733336 DOI: 10.1186/s13229-022-00527-0] [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: 05/10/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is the leading inherited monogenic cause of intellectual disability and autism spectrum disorder. Executive function (EF), necessary for adaptive goal-oriented behavior and dependent on frontal lobe function, is impaired in individuals with FXS. Yet, little is known how alterations in frontal lobe neural activity is related to EF deficits in FXS. METHODS Sixty-one participants with FXS (54% males) and 71 age- and sex-matched typically-developing controls (TDC; 58% males) completed a five-minute resting state electroencephalography (EEG) protocol and a computerized battery of tests of EF, the Test of Attentional Performance for Children (KiTAP). Following source localization (minimum-norm estimate), we computed debiased weighted phase lag index (dWPLI), a phase connectivity value, for pairings between 18 nodes in frontal regions for gamma (30-55 Hz) and alpha (10.5-12.5 Hz) bands. Linear models were generated with fixed factors of group, sex, frequency, and connection. Relationships between frontal connectivity and EF variables also were examined. RESULTS Individuals with FXS demonstrated increased gamma band and reduced alpha band connectivity across all frontal regions and across hemispheres compared to TDC. After controlling for nonverbal IQ, increased error rates on EF tasks were associated with increased gamma band and reduced alpha band connectivity. LIMITATIONS Frontal connectivity findings are limited to intrinsic brain activity during rest and may not generalize to frontal connectivity during EF tasks or everyday function. CONCLUSIONS We report gamma hyper-connectivity and alpha hypo-connectivity within source-localized frontal brain regions in FXS compared to TDC during resting-state EEG. For the first time in FXS, we report significant associations between EF and altered frontal connectivity, with increased error rate relating to increased gamma band connectivity and reduced alpha band connectivity. These findings suggest increased phase connectivity within gamma band may impair EF performance, whereas greater alpha band connectivity may provide compensatory support for EF. Together, these findings provide important insight into neurophysiological mechanisms of EF deficits in FXS and provide novel targets for treatment development.
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Affiliation(s)
- Lauren M. Schmitt
- grid.239573.90000 0000 9025 8099Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 4002, Cincinnati, OH 45229 USA ,grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Joy Li
- grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Rui Liu
- grid.239573.90000 0000 9025 8099Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 4002, Cincinnati, OH 45229 USA
| | - Paul S. Horn
- grid.239573.90000 0000 9025 8099Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 4002, Cincinnati, OH 45229 USA ,grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - John A. Sweeney
- grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Craig A. Erickson
- grid.239573.90000 0000 9025 8099Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 4002, Cincinnati, OH 45229 USA ,grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
| | - Ernest V. Pedapati
- grid.239573.90000 0000 9025 8099Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, MLC 4002, Cincinnati, OH 45229 USA ,grid.24827.3b0000 0001 2179 9593University of Cincinnati College of Medicine, Cincinnati, OH USA
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Maternal Microbiota Modulate a Fragile X-like Syndrome in Offspring Mice. Genes (Basel) 2022; 13:genes13081409. [PMID: 36011319 PMCID: PMC9407566 DOI: 10.3390/genes13081409] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/17/2022] [Accepted: 08/03/2022] [Indexed: 11/27/2022] Open
Abstract
Maternal microbial dysbiosis has been implicated in adverse postnatal health conditions in offspring, such as obesity, cancer, and neurological disorders. We observed that the progeny of mice fed a Westernized diet (WD) with low fiber and extra fat exhibited higher frequencies of stereotypy, hyperactivity, cranial features and lower FMRP protein expression, similar to what is typically observed in Fragile X Syndrome (FXS) in humans. We hypothesized that gut dysbiosis and inflammation during pregnancy influenced the prenatal uterine environment, leading to abnormal phenotypes in offspring. We found that oral in utero supplementation with a beneficial anti-inflammatory probiotic microbe, Lactobacillus reuteri, was sufficient to inhibit FXS-like phenotypes in offspring mice. Cytokine profiles in the pregnant WD females showed that their circulating levels of pro-inflammatory cytokine interleukin (Il)-17 were increased relative to matched gravid mice and to those given supplementary L. reuteri probiotic. To test our hypothesis of prenatal contributions to this neurodevelopmental phenotype, we performed Caesarian (C-section) births using dissimilar foster mothers to eliminate effects of maternal microbiota transferred during vaginal delivery or nursing after birth. We found that foster-reared offspring still displayed a high frequency of these FXS-like features, indicating significant in utero contributions. In contrast, matched foster-reared progeny of L. reuteri-treated mothers did not exhibit the FXS-like typical features, supporting a key role for microbiota during pregnancy. Our findings suggest that diet-induced dysbiosis in the prenatal uterine environment is strongly associated with the incidence of this neurological phenotype in progeny but can be alleviated by addressing gut dysbiosis through probiotic supplementation.
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