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McKinney WS, Bartolotti J, Khemani P, Wang JY, Hagerman RJ, Mosconi MW. Cerebellar-cortical function and connectivity during sensorimotor behavior in aging FMR1 gene premutation carriers. NEUROIMAGE-CLINICAL 2020; 27:102332. [PMID: 32711390 PMCID: PMC7381687 DOI: 10.1016/j.nicl.2020.102332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 12/13/2022]
Abstract
FMR1 premutation carriers show increased variability in motor control. Premutation carriers show reduced extrastriate activation during motor behavior. Premutation carriers show reduced extrastriate-cerebellar functional connectivity. Reduced extrastriate-cerebellar functional connectivity is related to motor issues.
Introduction Premutation carriers of the FMR1 gene are at risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disease characterized by motor, cognitive, and psychiatric decline as well as cerebellar and cerebral white matter pathology. Several studies have documented preclinical sensorimotor issues in aging premutation carriers, but the extent to which sensorimotor brain systems are affected and may represent early indicators of atypical neurodegeneration has not been determined. Materials and methods Eighteen healthy controls and 16 FMR1 premutation carriers (including five with possible, probable, or definite FXTAS) group-matched on age, sex, and handedness completed a visually guided precision gripping task with their right hand during fMRI. During the test, they used a modified pinch grip to press at 60% of their maximum force against a custom fiber-optic transducer. Participants viewed a horizontal white force bar that moved upward with increased force and downward with decreased force and a static target bar that was red during rest and turned green to cue the participant to begin pressing at the beginning of each trial. Participants were instructed to press so that the white force bar stayed as steady as possible at the level of the green target bar. Trials were 2-sec in duration and alternated with 2-sec rest periods. Five 24-sec blocks consisting of six trials were presented. Participants’ reaction time, the accuracy of their force relative to the target force, and the variability of their force accuracy across trials were examined. BOLD signal change and task-based functional connectivity (FC) were examined during force vs. rest. Results Relative to healthy controls, premutation carriers showed increased trial-to-trial variability of force output, though this was specific to younger premutation carriers in our sample. Relative to healthy controls, premutation carriers also showed reduced extrastriate activation during force relative to rest. FC between ipsilateral cerebellar Crus I and extrastriate cortex was reduced in premutation carriers compared to controls. Reduced Crus I-extrastriate FC was related to increased force accuracy variability in premutation carriers. Increased reaction time was associated with more severe clinically rated neurological abnormalities. Conclusions Findings of reduced activation in extrastriate cortex and reduced Crus I-extrastriate FC implicate deficient visual feedback processing and reduced cerebellar modulation of corrective motor commands. Our results are consistent with documented cerebellar pathology and visual-spatial processing in FXTAS and pre-symptomatic premutation carriers, and suggest FC alterations of cerebellar-cortical networks during sensorimotor behavior may represent a “prodromal” feature associated with FXTAS degeneration.
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Affiliation(s)
- Walker S McKinney
- Life Span Institute and Kansas Center for Autism Research and Training (K-CART), Clinical Child Psychology Program, University of Kansas, 1000 Sunnyside Avenue, Lawrence, KS 66045, USA.
| | - James Bartolotti
- Life Span Institute and Kansas Center for Autism Research and Training (K-CART), Clinical Child Psychology Program, University of Kansas, 1000 Sunnyside Avenue, Lawrence, KS 66045, USA.
| | - Pravin Khemani
- Department of Neurology, Swedish Neuroscience Institute, 550 17th Avenue, Suite 400, Seattle, WA 98122, USA.
| | - Jun Yi Wang
- Center for Mind and Brain, University of California, Davis, 267 Cousteau Place, Davis, CA 95618, USA.
| | - Randi J Hagerman
- MIND Institute and Department of Pediatrics, University of California, Davis School of Medicine, 2825 50th St., Sacramento, CA 95817, USA.
| | - Matthew W Mosconi
- Life Span Institute and Kansas Center for Autism Research and Training (K-CART), Clinical Child Psychology Program, University of Kansas, 1000 Sunnyside Avenue, Lawrence, KS 66045, USA.
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Hocking DR, Kraan CM, Godler DE, Bui QM, Li X, Bradshaw JL, Georgiou-Karistianis N, Metcalfe SA, Archibald AD, Turbitt E, Fielding J, Trollor J, Cohen J, Cornish KM. Evidence linking FMR1 mRNA and attentional demands of stepping and postural control in women with the premutation. Neurobiol Aging 2014; 36:1400-8. [PMID: 25541421 DOI: 10.1016/j.neurobiolaging.2014.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 09/25/2014] [Accepted: 11/21/2014] [Indexed: 10/24/2022]
Abstract
Recent studies in young adult females with the fragile X mental retardation 1 (FMR1) gene premutation (PM) have shown subtle but significant impairments in executive control and postural stability. Less is known about the influence of age and FMR1 gene expression on executive control and postural stability in females with the PM. Here, we examined the attentional demands of reactive stepping using a well-validated measure of choice stepping reaction time under dual-task interference. We explored the interrelationships between step initiation times during a concurrent verbal fluency task and specific impairments in executive control previously reported in females with the PM. Our results showed increased dual-task interference on step initiation times and variability in female PM compared with control subjects. In addition, we observed greater choice stepping reaction time dual-task costs above the breakpoint of 81 CGG repeats relative to below this CGG range. Dual-task interference on both reaction time and movement time were significantly predicted by low working memory capacity in female PM carriers. Importantly, we revealed that FMR1 messenger RNA level is the most significant predictor accounting for dual-task stepping variability in both reaction time and movement time in PM females. These findings for the first time provide evidence linking elevated FMR1 messenger RNA levels that have been previously associated with FMR1 RNA toxicity and deficits in cerebellar motor and cognitive networks in a subgroup of at-risk PM women.
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Affiliation(s)
- Darren R Hocking
- Olga Tennison Autism Research Centre, School of Psychological Science, La Trobe University, Bundoora, Victoria, Australia.
| | - Claudine M Kraan
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - David E Godler
- Cyto-molecular Diagnostics Research, Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Quang M Bui
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, University of Melbourne, Carlton, Victoria, Australia
| | - Xin Li
- Cyto-molecular Diagnostics Research, Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - John L Bradshaw
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Nellie Georgiou-Karistianis
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Sylvia A Metcalfe
- Genetics Education and Health Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Alison D Archibald
- Genetics Education and Health Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Parkville, Victoria, Australia
| | - Erin Turbitt
- Genetics Education and Health Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Joanne Fielding
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Julian Trollor
- Department of Developmental Disability Neuropsychiatry, School of Psychiatry, University of New South Wales, Sydney, Australia; Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Jonathan Cohen
- Genetics Education and Health Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia; Centre for Developmental Disability Health Victoria, Monash University, Clayton, Victoria, Australia; Fragile X Alliance Inc (Clinic and Resource Centre), North Caulfield, Victoria, Australia
| | - Kim M Cornish
- School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
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Grigsby J, Cornish K, Hocking D, Kraan C, Olichney JM, Rivera SM, Schneider A, Sherman S, Wang JY, Yang JC. The cognitive neuropsychological phenotype of carriers of the FMR1 premutation. J Neurodev Disord 2014; 6:28. [PMID: 25136377 PMCID: PMC4135346 DOI: 10.1186/1866-1955-6-28] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022] Open
Abstract
The fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder affecting a subset of carriers of the FMR1 (fragile X mental retardation 1) premutation. Penetrance and expression appear to be significantly higher in males than females. Although the most obvious aspect of the phenotype is the movement disorder that gives FXTAS its name, the disorder is also accompanied by progressive cognitive impairment. In this review, we address the cognitive neuropsychological and neurophysiological phenotype for males and females with FXTAS, and for male and female unaffected carriers. Despite differences in penetrance and expression, the cognitive features of the disorder appear similar for both genders, with impairment of executive functioning, working memory, and information processing the most prominent. Deficits in these functional systems may be largely responsible for impairment on other measures, including tests of general intelligence and declarative learning. FXTAS is to a large extent a white matter disease, and the cognitive phenotypes observed are consistent with what some have described as white matter dementia, in contrast to the impaired cortical functioning more characteristic of Alzheimer's disease and related disorders. Although some degree of impaired executive functioning appears to be ubiquitous among persons with FXTAS, the data suggest that only a subset of unaffected carriers of the premutation - both female and male - demonstrate such deficits, which typically are mild. The best-studied phenotype is that of males with FXTAS. The manifestations of cognitive impairment among asymptomatic male carriers, and among women with and without FXTAS, are less well understood, but have come under increased scrutiny.
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Affiliation(s)
- Jim Grigsby
- Department of Psychology, University of Colorado Denver, Denver, CO, USA ; Department of Medicine; Division of Health Care Policy and Research, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kim Cornish
- School of Psychology & Psychiatry; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - Darren Hocking
- Olga Tennison Autism Research Centre, School of Psychological Science, La Trobe University, Melbourne, Victoria, Australia
| | - Claudine Kraan
- School of Psychology & Psychiatry; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - John M Olichney
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Neurology, University of California, Davis, Sacramento, CA, USA
| | - Susan M Rivera
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Psychology, University of California-Davis, Sacramento, CA, USA ; MIND Institute, University of California-Davis Medical Center, Sacramento, CA, USA
| | - Andrea Schneider
- Center for Mind and Brain, University of California, Davis, CA, USA ; MIND Institute, University of California-Davis Medical Center, Sacramento, CA, USA
| | | | - Jun Yi Wang
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Pediatrics, University of California, Davis, Sacramento, CA, USA
| | - Jin-Chen Yang
- Center for Mind and Brain, University of California, Davis, CA, USA ; Department of Neurology, University of California, Davis, Sacramento, CA, USA
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Cognitive-motor interference during postural control indicates at-risk cerebellar profiles in females with the FMR1 premutation. Behav Brain Res 2013; 253:329-36. [PMID: 23896050 DOI: 10.1016/j.bbr.2013.07.033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/16/2013] [Accepted: 07/20/2013] [Indexed: 11/22/2022]
Abstract
Recent investigations report a higher risk of motor symptoms in females with the FMR1 premutation (PM-carriers) than has hitherto been appreciated. Here we examined basic sensorimotor and postural control under different sensory and attentional dual-task demands. Physiological performance and postural sway measures from the Physiological Profile Assessment (Lord et al., 2003 [39]) were conducted in 28 female PM-carriers (mean age: 41.32±8.03) and 31 female controls with normal FMR1 alleles (mean age: 41.61±8.3). Multiple regression analyses were conducted to examine the moderating role of CGG-repeat length on the relation between age and postural sway under dual-task interference. In female PM-carriers, our results showed significantly poorer proprioceptive awareness, slower reaction time, and greater postural displacement when performing a concurrent verbal fluency task. Significantly, these findings showed age- and genetically-modulated changes in dual-task postural displacement in the medio-lateral direction in female PM-carriers. These findings highlight the sensitivity of postural control paradigms in identifying early cerebellar postural changes that may act as surrogate markers of future decline in female PM-carriers.
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Neurobehavioural evidence for the involvement of the FMR1 gene in female carriers of fragile X syndrome. Neurosci Biobehav Rev 2013; 37:522-47. [DOI: 10.1016/j.neubiorev.2013.01.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 12/11/2012] [Accepted: 01/06/2013] [Indexed: 12/19/2022]
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Young adult male carriers of the fragile X premutation exhibit genetically modulated impairments in visuospatial tasks controlled for psychomotor speed. J Neurodev Disord 2012; 4:26. [PMID: 23148490 PMCID: PMC3506571 DOI: 10.1186/1866-1955-4-26] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 10/25/2012] [Indexed: 02/04/2023] Open
Abstract
Background A previous study reported enhanced psychomotor speed, and subtle but significant cognitive impairments, modulated by age and by mutations in the fragile X mental retardation 1 (FMR1) gene in adult female fragile X premutation carriers (fXPCs). Because male carriers, unlike females, do not have a second, unaffected FMR1 allele, male fXPCs should exhibit similar, if not worse, impairments. Understanding male fXPCs is of particular significance because of their increased risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS). Methods Male fXPCs (n = 18) and healthy control (HC) adults (n = 26) aged less than 45 years performed two psychomotor speed tasks (manual and oral) and two visuospatial tasks (magnitude comparison and enumeration). In the magnitude comparison task, participants were asked to compare and judge which of two bars was larger. In the enumeration task, participants were shown between one and eight green bars in the center of the screen, and asked to state the total number displayed. Enumeration typically proceeds in one of two modes: subitizing, a fast and accurate process that works only with a small set of items, and counting, which requires accurate serial-object detection and individuation during visual search. We examined the associations between the performance on all tasks and the age, full-scale intelligent quotient, and CGG repeat length of participants. Results We found that in the magnitude comparison and enumeration tasks, male fXPCs exhibited slower reaction times relative to HCs, even after controlling for simple reaction time. Conclusions Our results indicate that male fXPCs as a group show impairments (slower reaction times) in numerical visuospatial tasks, which are consistent with previous findings. This adds to a growing body of literature characterizing the phenotype in fXPCs who are asymptomatic for FXTAS. Future longitudinal studies are needed to determine how these impairments relate to risk of developing FXTAS.
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Hunsaker MR. Comprehensive neurocognitive endophenotyping strategies for mouse models of genetic disorders. Prog Neurobiol 2012; 96:220-41. [PMID: 22266125 PMCID: PMC3289520 DOI: 10.1016/j.pneurobio.2011.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 12/06/2011] [Accepted: 12/20/2011] [Indexed: 01/21/2023]
Abstract
There is a need for refinement of the current behavioral phenotyping methods for mouse models of genetic disorders. The current approach is to perform a behavioral screen using standardized tasks to define a broad phenotype of the model. This phenotype is then compared to what is known concerning the disorder being modeled. The weakness inherent in this approach is twofold: First, the tasks that make up these standard behavioral screens do not model specific behaviors associated with a given genetic mutation but rather phenotypes affected in various genetic disorders; secondly, these behavioral tasks are insufficiently sensitive to identify subtle phenotypes. An alternate phenotyping strategy is to determine the core behavioral phenotypes of the genetic disorder being studied and develop behavioral tasks to evaluate specific hypotheses concerning the behavioral consequences of the genetic mutation. This approach emphasizes direct comparisons between the mouse and human that facilitate the development of neurobehavioral biomarkers or quantitative outcome measures for studies of genetic disorders across species.
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Affiliation(s)
- Michael R Hunsaker
- Department of Neurological Surgery, University of California, Davis, Davis, CA 95616, USA.
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Goodrich-Hunsaker NJ, Wong LM, McLennan Y, Tassone F, Harvey D, Rivera SM, Simon TJ. Adult Female Fragile X Premutation Carriers Exhibit Age- and CGG Repeat Length-Related Impairments on an Attentionally Based Enumeration Task. Front Hum Neurosci 2011; 5:63. [PMID: 21808616 PMCID: PMC3139190 DOI: 10.3389/fnhum.2011.00063] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 06/27/2011] [Indexed: 01/25/2023] Open
Abstract
The high frequency of the fragile X premutation in the general population and its emerging neurocognitive implications highlight the need to investigate the effects of the premutation on lifespan cognitive development. Until recently, cognitive function in fragile X premutation carriers (fXPCs) was presumed to be unaffected by the mutation. Although as a group fXPCs did not differ from healthy controls (HCs), we show that young adult female fXPCs show subtle age- and significant fragile X mental retardation 1 (FMR1) gene mutation-modulated cognitive function as tested by a basic numerical enumeration task. These results indicate that older women with the premutation and fXPCs with greater CGG repeat lengths were at higher risk for difficulties in the deployment of volitional attention required to count 5–8 items, but spared performance when spatial shifts of attention were minimized to subitize a few (1–3). Results from the current study add to a growing body of evidence that suggests the premutation allele is associated with a subtle phenotype and implies that the cognitive demands necessary for counting are less effectively deployed in female fXPCs compared to HCs.
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Affiliation(s)
- Naomi J Goodrich-Hunsaker
- NeuroTherapeutics Research Institute, University of California Davis Medical Center Sacramento, CA, USA
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Abstract
A previous study reported preliminary results of enhanced processing of simple visual information in the form of faster reaction times, in female fragile X premutation carriers (fXPCs). In this study, we assessed manual and oral motor reaction times in 30 female fXPCs and 20 neurotypical (NT) controls. Participants completed two versions of the reaction time task; one version required a manual motor response and the other version required an oral motor response. Results revealed that the female fXPCs displayed faster reaction times for both manual and oral motor responses relative to NT controls. Molecular measures including CGG repeat length, FMR1 mRNA levels, and age were not associated with performance in either group. Given previously reported age and CGG repeat modulated performance on a magnitude comparison task in this same group of premutation carriers, results from the current study seem to suggest that female fXPCs may have spared basic psychomotor functionality.
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Visual pathway deficit in female fragile X premutation carriers: a potential endophenotype. Brain Cogn 2008; 69:291-5. [PMID: 18789568 DOI: 10.1016/j.bandc.2008.08.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/02/2008] [Accepted: 08/01/2008] [Indexed: 02/08/2023]
Abstract
Previous studies indicated impaired magnocellular (M) and relatively spared parvocellular (P) visual pathway functioning in patients with fragile X syndrome. In this study, we assessed M and P pathways in 22 female fragile X premutation carriers with normal intelligence and in 20 healthy non-carrier controls. Testing procedure included visual contrast sensitivity and vernier threshold measurements. Results revealed that carriers were selectively impaired on tests of M pathways (low spatial/high temporal frequency contrast sensitivity and frequency-doubling vernier), whereas they showed intact performance on P pathway tests. These results suggest that the deficit of the M pathway is an endophenotype of fragile X syndrome.
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Allen EG, Sherman S, Abramowitz A, Leslie M, Novak G, Rusin M, Scott E, Letz R. Examination of the effect of the polymorphic CGG repeat in the FMR1 gene on cognitive performance. Behav Genet 2005; 35:435-45. [PMID: 15971024 DOI: 10.1007/s10519-005-2792-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Accepted: 01/10/2005] [Indexed: 01/26/2023]
Abstract
A CGG repeat sequence located in the 5' untranslated region of the FMR1 gene is polymorphic with respect to size and stability of the repeat during parent-offspring transmission. When expanded to over 200 repeats, the gene is hypermethylated and silenced, leading to fragile X syndrome (FXS). Recently, alleles with large unmethylated repeat tracts (premutations) have been associated with ovarian failure and a late-onset tremor/ataxia syndrome, symptoms unrelated to FXS. To further investigate the phenotype consequence of high repeat alleles, we have analyzed Wechsler adult intelligence scales-III (WAIS-III) measures on 66 males and 217 females with a wide range of repeat sizes. Among females only, we found that FMR1 repeat size and transcript level significantly explained approximately 4% of the variance in the Verbal IQ summary measure, suggesting that this polymorphism is one of many factors that influence variation in cognitive performance. Because of the well established association of increasing repeat size with decreasing age at menopause, we also investigated the reproductive stage and use of hormone replacement therapy (HRT) as a covariate to model verbal intelligence quotient (VIQ). We found that it explained an additional 5% of the variance in VIQ, but did not interact with FMR1 repeat and transcript level.
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Block SS, Brusca-Vega R, Pizzi WJ, Berry-Kravis E, Maino DM, Treitman TM. Cognitive and visual processing skills and their relationship to mutation size in full and premutation female fragile X carriers. Optom Vis Sci 2000; 77:592-9. [PMID: 11138833 DOI: 10.1097/00006324-200011000-00009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The fragile X gene contains an unstable trinucleotide (CGG) repeat that expands as it is passed from female carriers to the affected offspring. Obligate female carriers may have a premutation or full mutation genotype. METHODS In this study, fragile X premutation and full mutation female carriers were compared on three tasks of visual processing and cognitive skills. RESULTS In each case, there were significant differences between premutation and full mutation carriers on a number of the subtests or the full test scores. Specifically, full mutation female carriers performed more poorly in visual-motor processing and analysis-synthesis on the Woodcock-Johnson Psycho-Educational Battery-Revised, The Developmental Test of Visual Motor Integration, and on five of the seven subtests of the Test of Visual-Perceptual Skills. Regression analyses revealed significant negative correlations between mutation size and cognitive ability. CONCLUSIONS These findings have implications in educational planning decisions for full mutation carriers who may present with specific cognitive deficits.
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Affiliation(s)
- S S Block
- Illinois College of Optometry, Chicago 60616-3816, USA
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Murray J, Cuckle H, Taylor G, Hewison J. Screening for fragile X syndrome: information needs for health planners. J Med Screen 1997; 4:60-94. [PMID: 9275266 DOI: 10.1177/096914139700400204] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J Murray
- Centre for Reproduction, Growth & Development, Research School of Medicine, University of Leeds, United Kingdom
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