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Tassone F, Protic D, Allen EG, Archibald AD, Baud A, Brown TW, Budimirovic DB, Cohen J, Dufour B, Eiges R, Elvassore N, Gabis LV, Grudzien SJ, Hall DA, Hessl D, Hogan A, Hunter JE, Jin P, Jiraanont P, Klusek J, Kooy RF, Kraan CM, Laterza C, Lee A, Lipworth K, Losh M, Loesch D, Lozano R, Mailick MR, Manolopoulos A, Martinez-Cerdeno V, McLennan Y, Miller RM, Montanaro FAM, Mosconi MW, Potter SN, Raspa M, Rivera SM, Shelly K, Todd PK, Tutak K, Wang JY, Wheeler A, Winarni TI, Zafarullah M, Hagerman RJ. Insight and Recommendations for Fragile X-Premutation-Associated Conditions from the Fifth International Conference on FMR1 Premutation. Cells 2023; 12:2330. [PMID: 37759552 PMCID: PMC10529056 DOI: 10.3390/cells12182330] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
The premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene is characterized by an expansion of the CGG trinucleotide repeats (55 to 200 CGGs) in the 5' untranslated region and increased levels of FMR1 mRNA. Molecular mechanisms leading to fragile X-premutation-associated conditions (FXPAC) include cotranscriptional R-loop formations, FMR1 mRNA toxicity through both RNA gelation into nuclear foci and sequestration of various CGG-repeat-binding proteins, and the repeat-associated non-AUG (RAN)-initiated translation of potentially toxic proteins. Such molecular mechanisms contribute to subsequent consequences, including mitochondrial dysfunction and neuronal death. Clinically, premutation carriers may exhibit a wide range of symptoms and phenotypes. Any of the problems associated with the premutation can appropriately be called FXPAC. Fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND) can fall under FXPAC. Understanding the molecular and clinical aspects of the premutation of the FMR1 gene is crucial for the accurate diagnosis, genetic counseling, and appropriate management of affected individuals and families. This paper summarizes all the known problems associated with the premutation and documents the presentations and discussions that occurred at the International Premutation Conference, which took place in New Zealand in 2023.
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Affiliation(s)
- Flora Tassone
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
| | - Dragana Protic
- Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, 11129 Belgrade, Serbia;
- Fragile X Clinic, Special Hospital for Cerebral Palsy and Developmental Neurology, 11040 Belgrade, Serbia
| | - Emily Graves Allen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Alison D. Archibald
- Victorian Clinical Genetics Services, Royal Children’s Hospital, Melbourne, VIC 3052, Australia;
- Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC 3052, Australia;
- Genomics in Society Group, Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Anna Baud
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznan, Poland; (A.B.); (K.T.)
| | - Ted W. Brown
- Central Clinical School, University of Sydney, Sydney, NSW 2006, Australia;
- Fragile X Association of Australia, Brookvale, NSW 2100, Australia;
- NYS Institute for Basic Research in Developmental Disabilities, New York, NY 10314, USA
| | - Dejan B. Budimirovic
- Department of Psychiatry, Fragile X Clinic, Kennedy Krieger Institute, Baltimore, MD 21205, USA;
- Department of Psychiatry & Behavioral Sciences-Child Psychiatry, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Jonathan Cohen
- Fragile X Alliance Clinic, Melbourne, VIC 3161, Australia;
| | - Brett Dufour
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Rachel Eiges
- Stem Cell Research Laboratory, Medical Genetics Institute, Shaare Zedek Medical Center Affiliated with the Hebrew University School of Medicine, Jerusalem 91031, Israel;
| | - Nicola Elvassore
- Veneto Institute of Molecular Medicine (VIMM), 35129 Padova, Italy; (N.E.); (C.L.)
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy
| | - Lidia V. Gabis
- Keshet Autism Center Maccabi Wolfson, Holon 5822012, Israel;
- Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - Samantha J. Grudzien
- Department of Neurology, University of Michigan, 4148 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA; (S.J.G.); (P.K.T.)
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Deborah A. Hall
- Department of Neurological Sciences, Rush University, Chicago, IL 60612, USA;
| | - David Hessl
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Abigail Hogan
- Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (A.H.); (J.K.)
| | - Jessica Ezzell Hunter
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Poonnada Jiraanont
- Faculty of Medicine, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand;
| | - Jessica Klusek
- Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (A.H.); (J.K.)
| | - R. Frank Kooy
- Department of Medical Genetics, University of Antwerp, 2000 Antwerp, Belgium;
| | - Claudine M. Kraan
- Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC 3052, Australia;
- Diagnosis and Development, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| | - Cecilia Laterza
- Veneto Institute of Molecular Medicine (VIMM), 35129 Padova, Italy; (N.E.); (C.L.)
- Department of Industrial Engineering, University of Padova, 35131 Padova, Italy
| | - Andrea Lee
- Fragile X New Zealand, Nelson 7040, New Zealand;
| | - Karen Lipworth
- Fragile X Association of Australia, Brookvale, NSW 2100, Australia;
| | - Molly Losh
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60201, USA;
| | - Danuta Loesch
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3086, Australia;
| | - Reymundo Lozano
- Departments of Genetics and Genomic Sciences and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Marsha R. Mailick
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA;
| | - Apostolos Manolopoulos
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, MD 21224, USA;
| | - Veronica Martinez-Cerdeno
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Yingratana McLennan
- Department of Pathology and Laboratory Medicine, Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children of Northern California, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | | | - Federica Alice Maria Montanaro
- Child and Adolescent Neuropsychiatry Unit, Department of Neuroscience, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy;
- Department of Education, Psychology, Communication, University of Bari Aldo Moro, 70121 Bari, Italy
| | - Matthew W. Mosconi
- Schiefelbusch Institute for Life Span Studies, University of Kansas, Lawrence, KS 66045, USA;
- Clinical Child Psychology Program, University of Kansas, Lawrence, KS 66045, USA
- Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, KS 66045, USA
| | - Sarah Nelson Potter
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Melissa Raspa
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Susan M. Rivera
- Department of Psychology, University of Maryland, College Park, MD 20742, USA;
| | - Katharine Shelly
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (E.G.A.); (P.J.); (K.S.)
| | - Peter K. Todd
- Department of Neurology, University of Michigan, 4148 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA; (S.J.G.); (P.K.T.)
- Ann Arbor Veterans Administration Healthcare, Ann Arbor, MI 48105, USA
| | - Katarzyna Tutak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznan, Poland; (A.B.); (K.T.)
| | - Jun Yi Wang
- Center for Mind and Brain, University of California Davis, Davis, CA 95618, USA;
| | - Anne Wheeler
- RTI International, Research Triangle Park, NC 27709, USA; (J.E.H.); (S.N.P.); (M.R.); (A.W.)
| | - Tri Indah Winarni
- Center for Biomedical Research (CEBIOR), Faculty of Medicine, Universitas Diponegoro, Semarang 502754, Central Java, Indonesia;
| | - Marwa Zafarullah
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California Davis, Sacramento, CA 95817, USA;
| | - Randi J. Hagerman
- MIND Institute, University of California Davis, Davis, CA 95817, USA; (B.D.); (D.H.); (V.M.-C.)
- Department of Pediatrics, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
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Sodhi DK, Hagerman R. Fragile X Premutation: Medications, Therapy and Lifestyle Advice. Pharmgenomics Pers Med 2022; 14:1689-1699. [PMID: 35002287 PMCID: PMC8721286 DOI: 10.2147/pgpm.s338846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022] Open
Abstract
The fragile X premutation is characterized by 55–200 CGG repeats in the 5ʹ untranslated region of FMR1, whereas full fragile X mutation has greater than 200 repeats and full methylation, which manifests as fragile X syndrome (FXS). The premutation spectrum of clinical involvement includes fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND). In addition, premutation carriers also suffer from various other health problems such as endocrine abnormalities and autoimmune problems. In this paper, we have discussed different health issues faced by the carriers and interventions including medications, therapy and lifestyle changes that could improve their health.
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Affiliation(s)
- Deepika Kour Sodhi
- The MIND Institute, University of California Davis Health, Sacramento, CA, USA
| | - Randi Hagerman
- The MIND Institute, University of California Davis Health, Sacramento, CA, USA.,Department of Pediatrics, University of California Davis Health, Sacramento, CA, USA
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Soorya LV, Fogg L, Ocampo E, Printen M, Youngkin S, Halpern D, Kolevzon A, Lee S, Grodberg D, Anagnostou E. Neurocognitive Outcomes from Memantine: A Pilot, Double-Blind, Placebo-Controlled Trial in Children with Autism Spectrum Disorder. J Child Adolesc Psychopharmacol 2021; 31:475-484. [PMID: 34543081 DOI: 10.1089/cap.2021.0010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Objective: Studies interrogating therapeutics which alter the excitation-inhibition balance in the treatment of autism spectrum disorder (ASD) have reported mixed results on social and behavioral outcomes. Methods: The aim of this randomized, double-blind placebo-controlled pilot trial was to evaluate neurocognitive effects of memantine over a 24-week trial. Twenty-three children ages 6-12 years old with ASD were randomized to memantine or placebo. Primary outcomes included measures of apraxia and expressive language with evaluations at midpoint (week 12) and endpoint (week 24). Secondary outcomes included memory and adaptive behavior measures. Exploratory outcomes included changes in overall cognitive functioning and behavior (e.g., Aberrant Behavior Checklist). Results: Results suggest that memantine was well-tolerated. Dropout rates were high across groups with only 14 participants completing the 6-month trial. Memantine was not associated with improvements in apraxia and expressive language. Treatment with memantine was associated with improvements in verbal recognition memory as measured by the Narrative Memory-Recognition (NEPSY-II) (F = 5.05, p = .03). In addition, exploratory analyses of changes in Intelligence quotient (IQ) suggest improvements on verbal IQ (d = 1.8). Conclusions: Results suggest future studies of memantine in ASD may benefit from shifting treatment targets from social and behavioral outcomes to exploration of effects of memantine on cognition, potentially as an adjunct to learning and educational interventions. ClinicalTrials.gov: NCT01372449.
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Affiliation(s)
- Latha Valluripalli Soorya
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Louis Fogg
- Department of Nursing, Rush University Medical Center, Chicago, Illinois, USA
| | - Edith Ocampo
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Madison Printen
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Sarah Youngkin
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Danielle Halpern
- Department of Psychiatry, Icahn School of Medicine, New York, New York, USA
| | - Alexander Kolevzon
- Department of Psychiatry, Icahn School of Medicine, New York, New York, USA
| | - Soo Lee
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - David Grodberg
- Child Study Center, Yale University, New Haven, Connecticut, USA
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Novel treatments for autism spectrum disorder based on genomics and systems biology. Pharmacol Ther 2021; 230:107939. [PMID: 34174273 DOI: 10.1016/j.pharmthera.2021.107939] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/03/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with a complex underlying genetic architecture. There are currently no known pharmacologic treatments for the core ASD symptoms of social deficits and restricted/ repetitive behavior. However, there are dozens of clinical trials currently underway that are testing the impact of novel and existing agents on core and associated symptoms in ASD. METHODS We present a narrative synthesis of the historical and contemporary challenges to drug discovery in ASD. We then provide an overview of novel treatments currently under investigation from a genomics and systems biology perspective. RESULTS Data driven network and cluster analyses suggest alterations in transcriptional regulation, chromatin remodelling, synaptic transmission, neuropeptide signalling, and/or immunological mechanisms may contribute to or underlie the development of ASD. Agents and upcoming trials targeting each of the above listed systems are reviewed. CONCLUSION Identifying effective pharmacologic treatments for the core and associated symptom domains in ASD will require further collaboration and innovation in the areas of outcome measurement, biomarker research, and genomics, as well as systematic efforts to identify and treat subgroups of individuals with ASD who may be differentially responsive to specific treatments.
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Abstract
PURPOSE OF REVIEW The purpose of this paper is to review the prevalence, pathophysiology, and management of fragile X-associated tremor/ataxia syndrome (FXTAS). RECENT FINDINGS The pathophysiology of FXTAS involves ribonucleic acid (RNA) toxicity due to elevated levels of the premutation-expanded CGG (eoxycytidylate-deoxyguanylate-deoxyguanylate)-repeat FMR1 mRNA, which can sequester a variety of proteins important for neuronal function. A recent analysis of the inclusions in FXTAS demonstrates elevated levels of several proteins, including small ubiquitin-related modifiers 1/2 (SUMO1/2), that target molecules for the proteasome, suggesting that some aspect(s) of proteasomal function may be altered in FXTAS. Recent neuropathological studies show that Parkinson disease and Alzheimer disease can sometimes co-occur with FXTAS. Lewy bodies can be found in 10% of the brains of patients with FXTAS. Microbleeds and iron deposition are also common in the neuropathology, in addition to white matter disease (WMD) and atrophy. SUMMARY The premutation occurs in 1:200 females and 1:400 males. Penetrance for FXTAS increases with age, though lower in females (16%) compared to over 60% of males by age 70. To diagnose FXTAS, an MRI is essential to document the presence of WMD, a primary component of the diagnostic criteria. Pain can be a significant feature of FXTAS and is seen in approximately 50% of patients.
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Holm KN, Herren AW, Taylor SL, Randol JL, Kim K, Espinal G, Martiínez-Cerdeño V, Pessah IN, Hagerman RJ, Hagerman PJ. Human Cerebral Cortex Proteome of Fragile X-Associated Tremor/Ataxia Syndrome. Front Mol Biosci 2021; 7:600840. [PMID: 33585555 PMCID: PMC7879451 DOI: 10.3389/fmolb.2020.600840] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 01/10/2023] Open
Abstract
Background: Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder associated with premutation CGG-repeat expansions (55–200 repeats) in the 5′ non-coding portion of the fragile X mental retardation 1 (FMR1) gene. Core features of FXTAS include progressive tremor/ataxia, cognitive decline, variable brain volume loss, and white matter disease. The principal histopathological feature of FXTAS is the presence of central nervous system (CNS) and non-CNS intranuclear inclusions. Objective: To further elucidate the molecular underpinnings of FXTAS through the proteomic characterization of human FXTAS cortexes. Results: Proteomic analysis of FXTAS brain cortical tissue (n = 8) identified minor differences in protein abundance compared to control brains (n = 6). Significant differences in FXTAS relative to control brain predominantly involved decreased abundance of proteins, with the greatest decreases observed for tenascin-C (TNC), cluster of differentiation 38 (CD38), and phosphoserine aminotransferase 1 (PSAT1); proteins typically increased in other neurodegenerative diseases. Proteins with the greatest increased abundance include potentially novel neurodegeneration-related proteins and small ubiquitin-like modifier 1/2 (SUMO1/2). The FMRpolyG peptide, proposed in models of FXTAS pathogenesis but only identified in trace amounts in the earlier study of FXTAS inclusions, was not identified in any of the FXTAS or control brains in the current study. Discussion: The observed proteomic shifts, while generally relatively modest, do show a bias toward decreased protein abundance with FXTAS. Such shifts in protein abundance also suggest altered RNA binding as well as loss of cell–cell adhesion/structural integrity. Unlike other neurodegenerative diseases, the proteome of end-stage FXTAS does not suggest a strong inflammation-mediated degenerative response.
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Affiliation(s)
- Katharine Nichole Holm
- Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Davis, CA, United States
| | - Anthony W Herren
- Mass Spectrometry Research Core, University of California Davis, Davis, CA, United States
| | - Sandra L Taylor
- Department of Public Health Sciences, Division of Biostatistics, University of California Davis School of Medicine, Davis, CA, United States
| | - Jamie L Randol
- Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Davis, CA, United States
| | - Kyoungmi Kim
- Department of Public Health Sciences, Division of Biostatistics, University of California Davis School of Medicine, Davis, CA, United States.,Medical Investigation of Neurodevelopmental Disorders Institute, University of California Davis School of Medicine, Davis, CA, United States
| | - Glenda Espinal
- Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Davis, CA, United States
| | - Verónica Martiínez-Cerdeño
- Medical Investigation of Neurodevelopmental Disorders Institute, University of California Davis School of Medicine, Davis, CA, United States.,Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Davis, CA, United States
| | - Isaac N Pessah
- Medical Investigation of Neurodevelopmental Disorders Institute, University of California Davis School of Medicine, Davis, CA, United States.,Department of Molecular Biosciences, University of California Davis School of Veterinary Medicine, Davis, CA, United States
| | - Randi J Hagerman
- Medical Investigation of Neurodevelopmental Disorders Institute, University of California Davis School of Medicine, Davis, CA, United States.,Department of Pediatrics, University of California Davis School of Medicine, Davis, CA, United States
| | - Paul J Hagerman
- Department of Biochemistry and Molecular Medicine, University of California Davis School of Medicine, Davis, CA, United States.,Medical Investigation of Neurodevelopmental Disorders Institute, University of California Davis School of Medicine, Davis, CA, United States
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Lepock JR, Ahmed S, Mizrahi R, Gerritsen CJ, Maheandiran M, Drvaric L, Bagby RM, Korostil M, Light GA, Kiang M. Relationships between cognitive event-related brain potential measures in patients at clinical high risk for psychosis. Schizophr Res 2020; 226:84-94. [PMID: 30683525 DOI: 10.1016/j.schres.2019.01.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 12/14/2022]
Abstract
Neurophysiological measures of cognitive functioning that are abnormal in patients with schizophrenia are promising candidate biomarkers for predicting development of psychosis in individuals at clinical high risk (CHR). We examined the relationships among event-related brain potential (ERP) measures of early sensory, pre-attentional, and attention-dependent cognition, in antipsychotic-naïve help-seeking CHR patients (n = 36) and healthy control participants (n = 22). These measures included the gamma auditory steady-state response (ASSR; early sensory); mismatch negativity (MMN) and P3a (pre-attentional); and N400 semantic priming effects - a measure of using meaningful context to predict related items - over a shorter and a longer time interval (attention-dependent). Compared to controls, CHR patients had significantly smaller P3a amplitudes (d = 0.62, p = 0.03) and N400 priming effects over the long interval (d = 0.64, p = 0.02). In CHR patients, gamma ASSR evoked power and phase-locking factor were correlated (r = 0.41, p = 0.03). Reductions in mismatch negativity (MMN) and P3a amplitudes were also correlated (r = -0.36, p = 0.04). Moreover, lower gamma ASSR evoked power correlated with smaller MMN amplitudes (r = -0.45, p = 0.02). MMN amplitude reduction was also associated with reduced N400 semantic priming over the shorter but not the longer interval (r = 0.52, p < 0.002). This pattern of results suggests that, in a subset of CHR patients, impairment in pre-attentional measures of early information processing may contribute to deficits in attention-dependent cognition involving rapid, more automatic processing, but may be independent from pathological processes affecting more controlled or strategic processing. Thus, combining neurophysiological indices of cognitive deficits in different domains offers promise for improving their predictive power as prognostic biomarkers of clinical outcome.
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Affiliation(s)
- Jennifer R Lepock
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Sarah Ahmed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Romina Mizrahi
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Cory J Gerritsen
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Graduate Department of Psychological Clinical Science, University of Toronto, Toronto, Ontario, Canada
| | | | - Lauren Drvaric
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - R Michael Bagby
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Graduate Department of Psychological Clinical Science, University of Toronto, Toronto, Ontario, Canada
| | - Michele Korostil
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Gregory A Light
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
| | - Michael Kiang
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
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8
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Li W, Kutas M, Gray JA, Hagerman RH, Olichney JM. The Role of Glutamate in Language and Language Disorders - Evidence from ERP and Pharmacologic Studies. Neurosci Biobehav Rev 2020; 119:217-241. [PMID: 33039453 DOI: 10.1016/j.neubiorev.2020.09.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 08/10/2020] [Accepted: 09/21/2020] [Indexed: 12/31/2022]
Abstract
Current models of language processing do not address mechanisms at the neurotransmitter level, nor how pharmacologic agents may improve language function(s) in seemingly disparate disorders. L-Glutamate, the primary excitatory neurotransmitter in the human brain, is extensively involved in various higher cortical functions. We postulate that the physiologic role of L-Glutamate neurotransmission extends to the regulation of language access, comprehension, and production, and that disorders in glutamatergic transmission and circuitry contribute to the pathogenesis of neurodegenerative diseases and sporadic-onset language disorders such as the aphasic stroke syndromes. We start with a review of basic science data pertaining to various glutamate receptors in the CNS and ways that they may influence the physiological processes of language access and comprehension. We then focus on the dysregulation of glutamate neurotransmission in three conditions in which language dysfunction is prominent: Alzheimer's Disease, Fragile X-associated Tremor/Ataxia Syndrome, and Aphasic Stroke Syndromes. Finally, we review the pharmacologic and electrophysiologic (event related brain potential or ERP) data pertaining to the role glutamate neurotransmission plays in language processing and disorders.
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Affiliation(s)
- Wentao Li
- Department of Neurology, University of California, Davis, 4860 Y Street, Suite 3700, Sacramento, CA, 95817, USA.
| | - Marta Kutas
- Department of Cognitive Science, University of California, San Diego, 9500 Gilman Drive #0515, La Jolla, CA, 92093, USA; Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
| | - John A Gray
- Department of Neurology, University of California, Davis, 4860 Y Street, Suite 3700, Sacramento, CA, 95817, USA; Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA, 95618, USA.
| | - Randi H Hagerman
- MIND Institute, University of California, Davis, 2825 50th Street, Sacramento, CA, 95817, USA.
| | - John M Olichney
- Department of Neurology, University of California, Davis, 4860 Y Street, Suite 3700, Sacramento, CA, 95817, USA; Center for Mind and Brain, University of California, Davis, 267 Cousteau Place, Davis, CA, 95618, USA.
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Choi JH, Shin C, Kim HJ, Jeon B. Placebo response in degenerative cerebellar ataxias: a descriptive review of randomized, placebo-controlled trials. J Neurol 2020; 269:62-71. [PMID: 33219422 DOI: 10.1007/s00415-020-10306-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/31/2020] [Accepted: 11/08/2020] [Indexed: 12/18/2022]
Abstract
Placebo response in degenerative cerebellar ataxias (CAs) has never been studied despite the large number of randomized controlled trials (RCTs) that have been conducted. In this descriptive review, we aimed to examine the placebo response in patients with CAs. We performed a literature search on PubMed for RCTs on CAs that were published from 1977 to January 2020 and collected data on the changes from the baseline to the endpoint on various objective ataxia-associated clinical rating scales. We reviewed 56 clinical trials, finally including 35 parallel-group studies and excluding 21 cross-over studies. The included studies were categorized as follows: (1) studies showing significant improvements in one or more ataxia scales in the placebo groups (n = 3); (2) studies reporting individual placebo responders with improvements in one or more ataxia scales in the placebo groups (n = 5)-the overall proportion of placebo responders was 31.9%; (3) studies showing mean changes in the direction of improvement in at least one ataxia scale in the placebo groups, though not statistically significant (n = 19); (4) studies showing no placebo response in any of the ataxia scales in the placebo groups (n = 4); (5) studies where data on the placebo groups were unavailable (n = 9). This review demonstrated the placebo response in patients with CAs on various objective ataxia scales. Our study emphasizes that the placebo response should be considered when designing, analyzing, and interpreting clinical trials and in clinical practice in CA patients.
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Affiliation(s)
- Ji-Hyun Choi
- Department of Neurology and Movement Disorder Center, Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.,Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Chaewon Shin
- Department of Neurology, Chungnam National University Sejong Hospital, Sejong-si, South Korea.,Department of Neurology, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Han-Joon Kim
- Department of Neurology and Movement Disorder Center, Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
| | - Beomseok Jeon
- Department of Neurology and Movement Disorder Center, Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
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10
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Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS): Pathophysiology and Clinical Implications. Int J Mol Sci 2020; 21:ijms21124391. [PMID: 32575683 PMCID: PMC7352421 DOI: 10.3390/ijms21124391] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
The fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder seen in older premutation (55-200 CGG repeats) carriers of FMR1. The premutation has excessive levels of FMR1 mRNA that lead to toxicity and mitochondrial dysfunction. The clinical features usually begin in the 60 s with an action or intention tremor followed by cerebellar ataxia, although 20% have only ataxia. MRI features include brain atrophy and white matter disease, especially in the middle cerebellar peduncles, periventricular areas, and splenium of the corpus callosum. Neurocognitive problems include memory and executive function deficits, although 50% of males can develop dementia. Females can be less affected by FXTAS because of a second X chromosome that does not carry the premutation. Approximately 40% of males and 16% of female carriers develop FXTAS. Since the premutation can occur in less than 1 in 200 women and 1 in 400 men, the FXTAS diagnosis should be considered in patients that present with tremor, ataxia, parkinsonian symptoms, neuropathy, and psychiatric problems. If a family history of a fragile X mutation is known, then FMR1 DNA testing is essential in patients with these symptoms.
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11
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Salcedo-Arellano MJ, Hagerman RJ, Martínez-Cerdeño V. [Fragile X associated tremor/ataxia syndrome: its clinical presentation, pathology, and treatment]. Rev Neurol 2019; 68:199-206. [PMID: 30805918 PMCID: PMC7001878 DOI: 10.33588/rn.6805.2018457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The fragile X associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disease associated with the repetition of CGG triplets (55-200 CGG repetitions) in the FMR1 gene. The premutation of the FMR1 gene, contrasting with the full mutation (more than 200 CGG repetitions), presents an increased production of messenger and a similar or slightly decreased production of FMRP protein. FXTAS affects 40% of men and 16% of women carriers of the premutation. It presents with a wide constellation of neurological signs such as intention tremor, cerebellar ataxia, parkinsonism, executive function deficits, peripheral neuropathy and cognitive decline leading to dementia among others. In this review, we present what is currently known about the molecular mechanism, the radiological findings and the pathology, as well as the complexity of the diagnosis and management of FXTAS.
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Affiliation(s)
- María Jimena Salcedo-Arellano
- Department of Pediatrics, University of California Davis
School of Medicine, Sacramento, CA, USA
- Medical Investigation of Neurodevelopmental Disorders
(MIND) Institute, University of California Davis, Sacramento, CA, USA
| | - Randi J Hagerman
- Department of Pediatrics, University of California Davis
School of Medicine, Sacramento, CA, USA
- Medical Investigation of Neurodevelopmental Disorders
(MIND) Institute, University of California Davis, Sacramento, CA, USA
| | - Verónica Martínez-Cerdeño
- Medical Investigation of Neurodevelopmental Disorders
(MIND) Institute, University of California Davis, Sacramento, CA, USA
- Institute for Pediatric Regenerative Medicine and Shriners
Hospitals for Children Northern California, Sacramento, CA, USA
- Department of Pathology and Laboratory Medicine, UC Davis
School of Medicine, Sacramento, CA, USA
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12
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Wang XH, Yang JC, Soohoo R, Cotter D, Yuan M, Xia J, Yaqub S, Doty J, Niu YQ, Tassone F, Hagerman R, Zhang L, Olichney J. Cognitive Deficits and Associated ERP N400 Abnormalities in FXTAS With Parkinsonism. Front Genet 2018; 9:327. [PMID: 30279697 PMCID: PMC6153313 DOI: 10.3389/fgene.2018.00327] [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: 01/10/2018] [Accepted: 07/31/2018] [Indexed: 11/13/2022] Open
Abstract
Objective: To examine cognitive deficits and associated brain activity in fragile X-associated tremor/ataxia syndrome (FXTAS) patients with parkinsonism (FXTp+), in relation to FXTAS patients without parkinsonism (FXTp-), and normal elderly controls (NC). Methods: Retrospective reviews were performed in 65 FXTAS patients who participated in the event-related brain potential (ERP) study and also had either a videotaped neurological examination or a neurological examination for extrapyramidal signs. Parkinsonism was defined as having bradykinesia with at least one of the following: rest tremor, postural instability, hypermyotonia, or rigidity. Eleven FXTp+ patients were identified and compared to 11 matched FXTp- and 11 NC. Main ERP measures included the N400 congruity effect, N400 repetition effect, and the late positive component (LPC) repetition effect. Results: When compared with FXTp- and NC, the FXTp+ group showed more severe deficits in executive function, cued-recall, recognition memory, along with a significantly reduced N400 repetition effect (thought to index semantic processing and verbal learning/memory) which was correlated with poorer verbal memory. Across all patients, FMR1 mRNA levels were inversely correlated with delayed recall on the California Verbal Learning Test (CVLT). Interpretation: The findings of more prominent executive dysfunction and verbal learning/memory deficits in FXTp+ than FXTp- are consistent with findings in Parkinson’s disease (PD), and may indicate that concomitant and/or synergistic pathogenetic mechanisms associated with PD play a role in FXTAS. These results have implications not only for understanding the cognitive impairments associated with the parkinsonism subtype of FXTAS, but also for the development of new interventions for these patients.
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Affiliation(s)
- Xiao-Hong Wang
- Department of Neurology, Dalian Municipal Central Hospital, Dalian, China.,Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Jin-Chen Yang
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States.,Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Robert Soohoo
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States.,Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Devyn Cotter
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States.,Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Mei Yuan
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States.,Department of Neurology, The Second Affiliated Hospital, University of South China, Hengyang, China
| | - Jiangyi Xia
- Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Shuja Yaqub
- Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Jesse Doty
- Center for Mind and Brain, University of California, Davis, Davis, CA, United States
| | - Yu-Qiong Niu
- Center for Mind and Brain, University of California, Davis, Davis, CA, United States.,MIND Institute, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Flora Tassone
- MIND Institute, School of Medicine, University of California, Davis, Davis, CA, United States.,Department of Biochemistry and Molecular Medicine, University of California, Davis, Davis, CA, United States
| | - Randi Hagerman
- MIND Institute, School of Medicine, University of California, Davis, Davis, CA, United States.,Department of Pediatrics, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Lin Zhang
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - John Olichney
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA, United States.,Center for Mind and Brain, University of California, Davis, Davis, CA, United States
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13
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Fragile X syndrome and fragile X-associated tremor ataxia syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2018; 147:377-391. [PMID: 29325626 DOI: 10.1016/b978-0-444-63233-3.00025-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Fragile X-associated disorders encompass several conditions, which are caused by expansion mutations in the fragile X mental retardation 1 (FMR1) gene. Fragile X syndrome is the most common inherited etiology of intellectual disability and results from a full mutation or >200 CGG repeats in FMR1. It is associated with developmental delay, autism spectrum disorder, and seizures. Fragile X-associated tremor/ataxia syndrome is a progressive neurodegenerative disease that occurs in premutation carriers of 55-200 CGG repeats in FMR1 and is characterized by kinetic tremor, gait ataxia, parkinsonism, executive dysfunction, and neuropathy. Fragile X-associated primary ovarian insufficiency also occurs in premutation carrier women and manifests with infertility and early menopause. The diseases constituting fragile X-associated disorders differ mechanistically, due to the distinct molecular properties of premutation versus full mutations. Fragile X syndrome occurs when there is a lack of fragile X mental retardation protein (FMRP) due to FMR1 methylation and silencing. In fragile X-associated tremor ataxia syndrome, a toxic gain of function is postulated with the production of excess CGG repeat-containing FMR1 mRNA, abnormal translation of the repeat sequence leading to production of polyglycine, polyalanine, and other polypeptides and to outright deficits in translation leading to reduced FMRP at larger premutation sizes. The changes in underlying brain chemistry due to FMR1 mutations have led to therapeutic studies in these disorders, with some progress being made in fragile X syndrome. This paper also summarizes indications for testing, genetic counseling issues, and what the future holds for these disorders.
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14
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Rajaratnam A, Shergill J, Salcedo-Arellano M, Saldarriaga W, Duan X, Hagerman R. Fragile X syndrome and fragile X-associated disorders. F1000Res 2017; 6:2112. [PMID: 29259781 PMCID: PMC5728189 DOI: 10.12688/f1000research.11885.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/20/2017] [Indexed: 12/26/2022] Open
Abstract
Fragile X syndrome (FXS) is caused by a full mutation on the
FMR1 gene and a subsequent lack of FMRP, the protein product of
FMR1. FMRP plays a key role in regulating the translation of many proteins involved in maintaining neuronal synaptic connections; its deficiency may result in a range of intellectual disabilities, social deficits, psychiatric problems, and dysmorphic physical features. A range of clinical involvement is also associated with the
FMR1 premutation, including fragile X-associated tremor ataxia syndrome, fragile X-associated primary ovarian insufficiency, psychiatric problems, hypertension, migraines, and autoimmune problems. Over the past few years, there have been a number of advances in our knowledge of FXS and fragile X-associated disorders, and each of these advances offers significant clinical implications. Among these developments are a better understanding of the clinical impact of the phenomenon known as mosaicism, the revelation that various types of mutations can cause FXS, and improvements in treatment for FXS.
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Affiliation(s)
| | | | | | - Wilmar Saldarriaga
- MIND Institute, UC Davis Health, Sacramento, CA, USA.,Department of Morphology and Obstetrics & Gynecology, Universidad del Valle, School of Medicine, Cali, Valle del Cauca, Colombia
| | - Xianlai Duan
- MIND Institute, UC Davis Health, Sacramento, CA, USA.,Department of Neurology, The Third Hospital of Changsha, Hunan Sheng, China
| | - Randi Hagerman
- MIND Institute, UC Davis Health, Sacramento, CA, USA.,Department of Pediatrics, University of California, Davis, School of Medicine, Sacramento, CA, USA
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15
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Wang JY, Trivedi AM, Carrillo NR, Yang J, Schneider A, Giulivi C, Adams P, Tassone F, Kim K, Rivera SM, Lubarr N, Wu CY, Irwin RW, Brinton RD, Olichney JM, Rogawski MA, Hagerman RJ. Open-Label Allopregnanolone Treatment of Men with Fragile X-Associated Tremor/Ataxia Syndrome. Neurotherapeutics 2017; 14:1073-1083. [PMID: 28707277 PMCID: PMC5722761 DOI: 10.1007/s13311-017-0555-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder affecting approximately 45% of male and 16% of female carriers of the FMR1 premutation over the age of 50 years. Currently, no effective treatment is available. We performed an open-label intervention study to assess whether allopregnanolone, a neurosteroid promoting regeneration and repair, can improve clinical symptoms, brain activity, and magnetic resonance imaging (MRI) measurements in patients with FXTAS. Six patients underwent weekly intravenous infusions of allopregnanolone (2-6 mg over 30 min) for 12 weeks. All patients completed baseline and follow-up studies, though MRI scans were not collected from 1 patient because of MRI contraindications. The MRI scans from previous visits, along with scans from 8 age-matched male controls, were also included to establish patients' baseline condition as a reference. Functional outcomes included quantitative measurements of tremor and ataxia and neuropsychological evaluations. Brain activity consisted of event-related potential N400 word repetition effect during a semantic memory processing task. Structural MRI outcomes comprised volumes of the hippocampus, amygdala, and fluid-attenuated inversion recovery hyperintensities, and microstructural integrity of the corpus callosum. The results of the study showed that allopregnanolone infusions were well tolerated in all subjects. Before treatment, the patients disclosed impairment in executive function, verbal fluency and learning, and progressive deterioration of all MRI measurements. After treatment, the patients demonstrated improvement in executive functioning, episodic memory and learning, and increased N400 repetition effect amplitude. Although MRI changes were not significant as a group, both improved and deteriorated MRI measurements occurred in individual patients in contrast to uniform deterioration before the treatment. Significant correlations between baseline MRI measurements and changes in neuropsychological test scores indicated the effects of allopregnanolone on improving executive function, learning, and memory for patients with relatively preserved hippocampus and corpus callosum, while reducing psychological symptoms for patients with small hippocampi and amygdalae. The findings show the promise of allopregnanolone in improving cognitive functioning in patients with FXTAS and in partially alleviating some aspects of neurodegeneration. Further studies are needed to verify the efficacy of allopregnanolone for treating FXTAS.
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Affiliation(s)
- J Y Wang
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - A M Trivedi
- School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - N R Carrillo
- School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - J Yang
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Center for Mind and Brain, University of California, Davis, Davis, CA, USA
| | - A Schneider
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Pediatrics, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - C Giulivi
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Molecular Biosciences, University of California Davis, School of Veterinary Medicine, Davis, CA, USA
| | - P Adams
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Pediatrics, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - F Tassone
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - K Kim
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Department of Public Health Sciences, University of California, Davis, Davis, CA, USA
| | - S M Rivera
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA
- Center for Mind and Brain, University of California, Davis, Davis, CA, USA
- Department of Psychology, University of California Davis, Davis, CA, USA
| | - N Lubarr
- Department of Neurology, Mount Sinai Beth Israel Hospital, New York, NY, USA
| | - C-Y Wu
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, USA
- PK/PD Bioanalytical Core Facility, UC Davis Health, Sacramento, CA, USA
| | - R W Irwin
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - R D Brinton
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
- Center for Innovation in Brain Science, School of Medicine, Departments of Pharmacology and Neurology, University of Arizona, Tucson, AZ, USA
| | - J M Olichney
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Center for Mind and Brain, University of California, Davis, Davis, CA, USA
| | - M A Rogawski
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Department of Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - R J Hagerman
- UC Davis MIND Institute, UC Davis Health, Sacramento, CA, USA.
- Department of Pediatrics, School of Medicine, University of California, Davis, Sacramento, CA, USA.
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16
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Budimirovic DB. Can a Neurosteroid Ameliorate Fragile X-Associated Tremor/Ataxia Syndrome? Neurotherapeutics 2017; 14:1070-1072. [PMID: 28884425 PMCID: PMC5722773 DOI: 10.1007/s13311-017-0569-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Dejan B Budimirovic
- Departments of Psychiatry and Behavioral Sciences, Kennedy Krieger Institute and Child Psychiatry, The Johns Hopkins Medical Institutions, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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17
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Budimirovic DB, Berry-Kravis E, Erickson CA, Hall SS, Hessl D, Reiss AL, King MK, Abbeduto L, Kaufmann WE. Updated report on tools to measure outcomes of clinical trials in fragile X syndrome. J Neurodev Disord 2017; 9:14. [PMID: 28616097 PMCID: PMC5467057 DOI: 10.1186/s11689-017-9193-x] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/22/2017] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Fragile X syndrome (FXS) has been the neurodevelopmental disorder with the most active translation of preclinical breakthroughs into clinical trials. This process has led to a critical assessment of outcome measures, which resulted in a comprehensive review published in 2013. Nevertheless, the disappointing outcome of several recent phase III drug trials in FXS, and parallel efforts at evaluating behavioral endpoints for trials in autism spectrum disorder (ASD), has emphasized the need for re-assessing outcome measures and revising recommendations for FXS. METHODS After performing an extensive database search (PubMed, Food and Drug Administration (FDA)/National Institutes of Health (NIH)'s www.ClinicalTrials.gov, etc.) to determine progress since 2013, members of the Working Groups who published the 2013 Report evaluated the available outcome measures for FXS and related neurodevelopmental disorders using the COSMIN grading system of levels of evidence. The latter has also been applied to a British survey of endpoints for ASD. In addition, we also generated an informal classification of outcome measures for use in FXS intervention studies as instruments appropriate to detect shorter- or longer-term changes. RESULTS To date, a total of 22 double-blind controlled clinical trials in FXS have been identified through www.ClinicalTrials.gov and an extensive literature search. The vast majority of these FDA/NIH-registered clinical trials has been completed between 2008 and 2015 and has targeted the core excitatory/inhibitory imbalance present in FXS and other neurodevelopmental disorders. Limited data exist on reliability and validity for most tools used to measure cognitive, behavioral, and other problems in FXS in these trials and other studies. Overall, evidence for most tools supports a moderate tool quality grading. Data on sensitivity to treatment, currently under evaluation, could improve ratings for some cognitive and behavioral tools. Some progress has also been made at identifying promising biomarkers, mainly on blood-based and neurophysiological measures. CONCLUSION Despite the tangible progress in implementing clinical trials in FXS, the increasing data on measurement properties of endpoints, and the ongoing process of new tool development, the vast majority of outcome measures are at the moderate quality level with limited information on reliability, validity, and sensitivity to treatment. This situation is not unique to FXS, since reviews of endpoints for ASD have arrived at similar conclusions. These findings, in conjunction with the predominance of parent-based measures particularly in the behavioral domain, indicate that endpoint development in FXS needs to continue with an emphasis on more objective measures (observational, direct testing, biomarkers) that reflect meaningful improvements in quality of life. A major continuous challenge is the development of measurement tools concurrently with testing drug safety and efficacy in clinical trials.
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Affiliation(s)
- Dejan B. Budimirovic
- Departments of Psychiatry and Behavioral Sciences, Kennedy Krieger Institute and Child Psychiatry, Johns Hopkins University School of Medicine, 716 N. Broadway, Baltimore, MD 21205 USA
| | - Elizabeth Berry-Kravis
- Departments of Pediatrics, Neurological Sciences, Biochemistry, Rush University Medical Center, 1725 West Harrison, Suite 718, Chicago, IL 60612 USA
| | - Craig A. Erickson
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center and the University of Cincinnati College of Medicine, 3333 Burnet Avenue MLC 4002, Cincinnati, OH 45229 USA
| | - Scott S. Hall
- Division of Interdisciplinary Brain Sciences, Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - David Hessl
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Allan L. Reiss
- Division of Interdisciplinary Brain Sciences, Departments of Psychiatry and Behavioral Sciences, Radiology and Pediatrics, Stanford University, 401 Quarry Road, Stanford, CA 94305 USA
| | - Margaret K. King
- Autism & Developmental Medicine Institute, Geisinger Health System, Present address: Novartis Pharmaceuticals Corporation, US Medical, One Health Plaza, East Hanover, NJ 07936 USA
| | - Leonard Abbeduto
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 2825 50th Street, Sacramento, CA 95817 USA
| | - Walter E. Kaufmann
- Center for Translational Research, Greenwood Genetic Center, 113 Gregor Mendel Circle, Greenwood, SC 29646 USA
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115 USA
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18
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Pugin A, Faundes V, Santa María L, Curotto B, Aliaga S, Salas I, Soto P, Bravo P, Peña M, Alliende M. Clinical, molecular, and pharmacological aspects of FMR1 -related disorders. NEUROLOGÍA (ENGLISH EDITION) 2017. [DOI: 10.1016/j.nrleng.2014.10.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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19
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Connon P, Larner AJ. Fragile X-associated tremor/ataxia syndrome: cognitive presentations. Br J Hosp Med (Lond) 2017; 78:230-231. [PMID: 28398884 DOI: 10.12968/hmed.2017.78.4.230] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- P Connon
- Core Medical Trainee year 2 (CMT2), Cognitive Function Clinic, Walton Centre for Neurology and Neurosurgery, Liverpool
| | - A J Larner
- Consultant Neurologist, Cognitive Function Clinic, Walton Centre for Neurology and Neurosurgery, Liverpool L9 7LJ
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20
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Braga Neto P, Pedroso JL, Kuo SH, Marcondes Junior CF, Teive HAG, Barsottini OGP. Current concepts in the treatment of hereditary ataxias. ARQUIVOS DE NEURO-PSIQUIATRIA 2017; 74:244-52. [PMID: 27050855 DOI: 10.1590/0004-282x20160038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/04/2016] [Indexed: 02/19/2023]
Abstract
Hereditary ataxias (HA) represents an extensive group of clinically and genetically heterogeneous neurodegenerative diseases, characterized by progressive ataxia combined with extra-cerebellar and multi-systemic involvements, including peripheral neuropathy, pyramidal signs, movement disorders, seizures, and cognitive dysfunction. There is no effective treatment for HA, and management remains supportive and symptomatic. In this review, we will focus on the symptomatic treatment of the main autosomal recessive ataxias, autosomal dominant ataxias, X-linked cerebellar ataxias and mitochondrial ataxias. We describe management for different clinical symptoms, mechanism-based approaches, rehabilitation therapy, disease modifying therapy, future clinical trials and perspectives, genetic counseling and preimplantation genetic diagnosis.
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Affiliation(s)
- Pedro Braga Neto
- Center of Health Sciences, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - José Luiz Pedroso
- Departmento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Sheng-Han Kuo
- Department of Neurology, Columbia University, New York, NY, United States
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21
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Abstract
Tremor is a frequent patient complaint in the neurologist's office. Nevertheless, despite the routine nature of this office presentation, misdiagnosis of common tremors is not an infrequent practice. In addition, there are less common causes of tremor that can be missed if the clinician is not aware of key features. An organized and methodical history and neurologic examination are essential in developing the differential diagnosis in tremor patients and ultimately in achieving the correct diagnosis. Awareness of key historical features associated with tremor and knowledge of the movement disorders examination will improve tremor assessment.
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Affiliation(s)
- Vicki L Shanker
- Neurology, Icahn School of Medicine at Mount Sinai, 10 Union Square East, Suite 5H, New York, NY 10003, USA.
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22
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Abstract
Many physicians are unaware of the many phenotypes associated with the fragile X premutation, an expansion in the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene that consists of 55-200 CGG repeats. The most severe of these phenotypes is fragile X-associated tremor/ataxia syndrome (FXTAS), which occurs in the majority of ageing male premutation carriers but in fewer than 20% of ageing women with the premutation. The prevalence of the premutation is 1 in 150-300 females, and 1 in 400-850 males, so physicians are likely to see people affected by FXTAS. Fragile X DNA testing is broadly available in the Western world. The clinical phenotype of FXTAS at presentation can vary and includes intention tremor, cerebellar ataxia, neuropathic pain, memory and/or executive function deficits, parkinsonian features, and psychological disorders, such as depression, anxiety and/or apathy. FXTAS causes brain atrophy and white matter disease, usually in the middle cerebellar peduncles, the periventricular area, and the splenium and/or genu of the corpus callosum. Here, we review the complexities involved in the clinical management of FXTAS and consider how targeted treatment for these clinical features of FXTAS will result from advances in our understanding of the molecular mechanisms that underlie this neurodegenerative disorder. Such targeted approaches should also be more broadly applicable to earlier forms of clinical involvement among premutation carriers.
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Brühl AB, Sahakian BJ. Drugs, games, and devices for enhancing cognition: implications for work and society. Ann N Y Acad Sci 2016; 1369:195-217. [PMID: 27043232 DOI: 10.1111/nyas.13040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/15/2016] [Accepted: 02/18/2016] [Indexed: 12/11/2022]
Abstract
As work environments change, the demands on working people change. Cognitive abilities in particular are becoming progressively more important for work performance and successful competition in a global environment. However, work-related stress, performance over long hours, lack of sleep, shift work, and jet lag affect cognitive functions. Therefore, an increasing number of healthy people are reported to use cognitive-enhancing drugs, as well as other interventions, such as noninvasive brain stimulation, to maintain or improve work performance. This review summarizes research on pharmacological and technical methods as well as cognitive training, including game apps for the brain, in healthy people. In neuropsychiatric disorders, impairments in cognitive functions can drastically reduce the chances of returning to work; therefore, this review also summarizes findings from pharmacological and cognitive-training studies in neuropsychiatric disorders.
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Affiliation(s)
- Annette B Brühl
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry Zurich, Zürich, Switzerland
| | - Barbara J Sahakian
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
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Abstract
PURPOSE OF REVIEW Psychotropic medications are commonly prescribed to people with intellectual disability. We reviewed current evidence-based pharmacotherapy options and recent updates to guide clinicians in their medication management plans. RECENT FINDINGS Antipsychotics, particularly risperidone, appear to be effective in reducing problem behaviors in children with intellectual disability. Evidence in adults is inconclusive. Methylphenidate appears to be effective, and α-agonists appear promising in reducing attention-deficit hyperactivity disorder symptoms. Lithium might be effective in reducing aggression. Evidence is limited to support the use of antiepileptic drugs, anxiolytics, and naltrexone for management of problem behaviors. Antidepressants may be poorly tolerated and might not be effective in reducing repetitive/stereotypic behaviors.In recent trials, glutamatergic and GABAergic agents for fragile X syndrome, and acetylcholinesterase inhibitors for Down's syndrome, failed to show efficacy. Growth hormone treatment might improve cognition and behavior in Prader-Willi syndrome population. Results from oxytocin trials on social behaviors are inconclusive albeit promising. Melatonin appears to improve sleep. Most trials of dietary supplements did not show benefits. SUMMARY Evidence-based pharmacotherapy options in people with intellectual disability are limited, and many agents can cause substantial adverse events. For this reason, clinicians should consider pharmacotherapy as only a part of comprehensive treatment, and regularly assess drug effects, adverse events, and the feasibility of decreasing dose or withdrawing medications.
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Yang JC, Rodriguez A, Royston A, Niu YQ, Avar M, Brill R, Simon C, Grigsby J, Hagerman RJ, Olichney JM. Memantine Improves Attentional Processes in Fragile X-Associated Tremor/Ataxia Syndrome: Electrophysiological Evidence from a Randomized Controlled Trial. Sci Rep 2016; 6:21719. [PMID: 26898832 PMCID: PMC4761982 DOI: 10.1038/srep21719] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/29/2016] [Indexed: 11/24/2022] Open
Abstract
Progressive cognitive deficits are common in patients with fragile X-associated tremor/ataxia syndrome (FXTAS), with no targeted treatment yet established. In this substudy of the first randomized controlled trial for FXTAS, we examined the effects of NMDA antagonist memantine on attention and working memory. Data were analyzed for patients (24 in each arm) who completed both the primary memantine trial and two EEG recordings (at baseline and follow-up) using an auditory “oddball” task. Results demonstrated significantly improved attention/working memory performance after one year only for the memantine group. The event-related potential P2 amplitude elicited by non-targets was significantly enhanced in the treated group, indicating memantine-associated improvement in attentional processes at the stimulus identification/discrimination level. P2 amplitude increase was positively correlated with improvement on the behavioral measure of attention/working memory during target detection. Analysis also revealed that memantine treatment normalized the P2 habituation effect at the follow-up visit. These findings indicate that memantine may benefit attentional processes that represent fundamental components of executive function/dysfunction, thought to comprise the core cognitive deficit in FXTAS. The results provide evidence of target engagement of memantine, as well as therapeutically relevant information that could further the development of specific cognitive or disease-modifying therapies for FXTAS.
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Affiliation(s)
- Jin-Chen Yang
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Neurology, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
| | - Annette Rodriguez
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Psychology, California State University, Sacramento, Sacramento, CA, 95819 USA
| | - Ashley Royston
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Psychology, University of California Davis, Davis, CA, 95616 USA
| | - Yu-Qiong Niu
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Neurology, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
| | - Merve Avar
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,University of Vienna, Vienna, 1010 Austria
| | - Ryan Brill
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Neurology, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
| | - Christa Simon
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Neurology, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
| | - Jim Grigsby
- Department of Psychology, Department of Medicine, University of Colorado Denver, Denver, CO, 80217 USA
| | - Randi J Hagerman
- Medical Investigation of Neurodevelopmental Disorders (M.I.N.D.) Institute, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA.,Department of Pediatrics, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
| | - John M Olichney
- Center for Mind and Brain, University of California Davis, Davis, CA, 95618 USA.,Department of Neurology, University of California Davis, School of Medicine, Sacramento, CA, 95817 USA
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26
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Hagerman PJ, Hagerman RJ. Fragile X-associated tremor/ataxia syndrome. Ann N Y Acad Sci 2015; 1338:58-70. [PMID: 25622649 PMCID: PMC4363162 DOI: 10.1111/nyas.12693] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/04/2014] [Accepted: 12/18/2014] [Indexed: 12/20/2022]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that affects some but not all carriers of small, noncoding CGG-repeat expansions (55-200 repeats; premutation) within the fragile X gene (FMR1). Principal features of FXTAS include intention tremor, cerebellar ataxia, Parkinsonism, memory and executive function deficits, autonomic dysfunction, brain atrophy with white matter disease, and cognitive decline. Although FXTAS was originally considered to be confined to the premutation range, rare individuals with a gray zone (45-54 repeats) or an unmethylated full mutation (>200 repeats) allele have now been described, the constant feature of the disorder remaining the requirement for FMR1 expression, in contradistinction to the gene silencing mechanism of fragile X syndrome. Although transcriptional activity is required for FXTAS pathogenesis, the specific trigger(s) for FXTAS pathogenesis remains elusive, highlighting the need for more research in this area. This need is underscored by recent neuroimaging findings of changes in the central nervous system that consistently appear well before the onset of clinical symptoms, thus creating an opportunity to delay or prevent the appearance of FXTAS.
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Affiliation(s)
- Paul J Hagerman
- Department of Biochemistry and Molecular Medicine, University of California , Davis , School of Medicine, Davis, California; The MIND Institute, University of California , Davis , Health System, Sacramento, California
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Pugin A, Faundes V, Santa María L, Curotto B, Aliaga S, Salas I, Soto P, Bravo P, Peña MI, Alliende MA. Clinical, molecular, and pharmacological aspects of FMR1 related disorders. Neurologia 2014; 32:241-252. [PMID: 25529181 DOI: 10.1016/j.nrl.2014.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 10/08/2014] [Accepted: 10/23/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Fragile X syndrome, the most common inherited cause of intellectual disability, is associated with a broad spectrum of disorders across different generations of a single family. This study reviews the clinical manifestations of fragile X-associated disorders as well as the spectrum of mutations of the fragile X mental retardation 1 gene (FMR1) and the neurobiology of the fragile X mental retardation protein (FMRP), and also provides an overview of the potential therapeutic targets and genetic counselling. DEVELOPMENT This disorder is caused by expansion of the CGG repeat (>200 repeats) in the 5 prime untranslated region of FMR1, resulting in a deficit or absence of FMRP. FMRP is an RNA-binding protein that regulates the translation of several genes that are important in synaptic plasticity and dendritic maturation. It is believed that CGG repeat expansions in the premutation range (55 to 200 repeats) elicit an increase in mRNA levels of FMR1, which may cause neuronal toxicity. These changes manifest clinically as developmental problems such as autism and learning disabilities as well as neurodegenerative diseases including fragile X-associated tremor/ataxia syndrome (FXTAS). CONCLUSIONS Advances in identifying the molecular basis of fragile X syndrome may help us understand the causes of neuropsychiatric disorders, and they will probably contribute to development of new and specific treatments.
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Affiliation(s)
- A Pugin
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - V Faundes
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.
| | - L Santa María
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - B Curotto
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - S Aliaga
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - I Salas
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - P Soto
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - P Bravo
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - M I Peña
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - M A Alliende
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
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28
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Muzar Z, Lozano R. Current research, diagnosis, and treatment of fragile X-associated tremor/ataxia syndrome. Intractable Rare Dis Res 2014; 3:101-9. [PMID: 25606360 PMCID: PMC4298640 DOI: 10.5582/irdr.2014.01029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/30/2014] [Indexed: 12/13/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is caused by a premutation CGG-repeat expansion in the 5'UTR of the fragile X mental retardation 1 (FMR1) gene. The classical clinical manifestations include tremor, cerebellar ataxia, cognitive decline and psychiatric disorders. Other less frequent features are peripheral neuropathy and autonomic dysfunction. Cognitive decline, a form of frontal subcortical dementia, memory loss and executive function deficits are also characteristics of this disorder. In this review, we present an expansion of recommendations for genetic testing for adults with suspected premutation disorders and provide an update of the clinical, radiological and molecular research of FXTAS, as well as the current research in the treatment for this intractable complex neurodegenerative genetic disorder.
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Affiliation(s)
- Zukhrofi Muzar
- UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA
| | - Reymundo Lozano
- UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA
- Address correspondence to: Dr. Reymundo Lozano, UC Davis MIND Institute and Department of Pediatrics, UC Davis Medical Center, Sacramento, CA, USA. E-mail:
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29
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Yang JC, Chi L, Teichholtz S, Schneider A, Nanakul R, Nowacki R, Seritan A, Reed B, DeCarli C, Iragui VJ, Kutas M, Hagerman PJ, Hagerman RJ, Olichney JM. ERP abnormalities elicited by word repetition in fragile X-associated tremor/ataxia syndrome (FXTAS) and amnestic MCI. Neuropsychologia 2014; 63:34-42. [PMID: 25111034 DOI: 10.1016/j.neuropsychologia.2014.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 07/31/2014] [Accepted: 08/01/2014] [Indexed: 01/26/2023]
Abstract
BACKGROUND Fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disorder caused by FMR1 gene premutations, typically associated with frontal-subcortical type cognitive impairments. High prevalence (~50%) of superimposed Alzheimer׳s pathology has been reported in FMR1 premutation carriers, and standardized neuropsychological tests have not yielded any robust discriminators between FXTAS and Alzheimer׳s disease (AD) dementia. The similarities/differences in memory processes between FXTAS and early AD remain underexplored. METHODS 32-channel event-related potentials (ERPs) were obtained from a semantic judgment task in which semantically congruous (50%) and incongruous pairs repeat pseudorandomly. The N400 and late positive component (LPC) of 25 FXTAS patients (M(age)=71.2, MMSE=26.6) were compared to a matched group of 25 patients with MCI or early AD (1 mild AD dementia, 24 amnestic MCI, of whom 18 later converted to AD; M(age)=73.4, MMSE=26.4), and 25 healthy elderly. RESULTS Both patient groups showed similar reductions in the N400 repetition effect and N400 congruity effect amplitudes, compared to controls, reflecting abnormal semantic priming and repetition priming. The MCI/AD group, however, had significantly smaller LPC word repetition effects and poorer learning and memory on the CVLT than FXTAS. The LPC and N400 repetition effects both correlated with verbal memory across all subjects, but only N400 correlated with memory in FXTAS. CONCLUSION FXTAS patients show relative sparing of the LPC repetition effect, and less disruption of explicit memory than prodromal/early AD. N400 abnormalities in FXTAS appear to account for much of their mild impairments in verbal learning and memory.
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Affiliation(s)
- Jin-Chen Yang
- University of California Davis, Center for Mind and Brain, Davis, CA 95618-5412, USA; University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA.
| | - Lillian Chi
- University of California Davis, Center for Mind and Brain, Davis, CA 95618-5412, USA; University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA
| | - Sara Teichholtz
- University of California Davis, Center for Mind and Brain, Davis, CA 95618-5412, USA; University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA
| | - Andrea Schneider
- University of California Davis, M.I.N.D. Institute, School of Medicine, Sacramento, CA, USA; University of California Davis, Department of Pediatrics, School of Medicine, Sacramento, CA, USA
| | - Rawi Nanakul
- University of California Davis, Center for Mind and Brain, Davis, CA 95618-5412, USA; University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA
| | - Ralph Nowacki
- University of California San Diego, Department of Neurosciences, San Diego, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA
| | - Andreea Seritan
- University of California Davis, Department of Psychiatry and Behavioral Sciences, School of Medicine, Sacramento, CA, USA
| | - Bruce Reed
- University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA
| | - Charles DeCarli
- University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA
| | - Vicente J Iragui
- University of California San Diego, Department of Neurosciences, San Diego, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA
| | - Marta Kutas
- University of California San Diego, Department of Cognitive Sciences, San Diego, CA, USA
| | - Paul J Hagerman
- University of California Davis, Department of Biochemistry and Molecular Medicine, Davis, CA, USA
| | - Randi J Hagerman
- University of California Davis, M.I.N.D. Institute, School of Medicine, Sacramento, CA, USA; University of California Davis, Department of Pediatrics, School of Medicine, Sacramento, CA, USA
| | - John M Olichney
- University of California Davis, Center for Mind and Brain, Davis, CA 95618-5412, USA; University of California Davis, Department of Neurology, School of Medicine, Sacramento, CA 95618-5412, USA.
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