title: Exploring inhibitory deficits in female premutation carriers of fragile X syndrome: through eye movements.
abstract: There is evidence which demonstrates that a subset of males with a premutation CGG repeat expansion (between 55 and 200 repeats) of the fragile X mental retardation 1 gene exhibit subtle deficits of executive function that progressively deteriorate with increasing age and CGG repeat length. However, it remains unclear whether similar deficits, which may indicate the onset of more severe degeneration, are evident in female PM-carriers. In the present study we explore whether female PM-carriers exhibit deficits of executive function which parallel those of male PM-carriers. Fourteen female fragile X premutation carriers without fragile X-associated tremor/ataxia syndrome and fourteen age, sex, and IQ matched controls underwent ocular motor and neuropsychological tests of select executive processes, specifically of response inhibition and working memory. Group comparisons revealed poorer inhibitory control for female premutation carriers on ocular motor tasks, in addition to demonstrating some difficulties in behaviour self-regulation, when compared to controls. A negative correlation between CGG repeat length and antisaccade error rates for premutation carriers was also found. Our preliminary findings indicate that impaired inhibitory control may represent a phenotype characteristic which may be a sensitive risk biomarker within this female fragile X premutation population.
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Annie L
authors.initials: AL
authors.lastname: Shelton
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Kim
authors.initials: K
authors.lastname: Cornish
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Claudine
authors.initials: C
authors.lastname: Kraan
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Nellie
authors.initials: N
authors.lastname: Georgiou-Karistianis
authors.affiliation: Genetics Education and Health Research, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria 3052, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3025, Australia.
authors.forename: Sylvia A
authors.initials: SA
authors.lastname: Metcalfe
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: John L
authors.initials: JL
authors.lastname: Bradshaw
authors.affiliation: Olga Tennison Autism Research Centre, School of Psychological Science, La Trobe University, Bundoora 3086, Australia.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Hocking
authors.affiliation: Genetics Education and Health Research, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria 3052, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3025, Australia; Victorian Clinical Genetics Services, Flemington Rd, Parkville, Victoria 3052, Australia.
authors.forename: Alison D
authors.initials: AD
authors.lastname: Archibald
authors.affiliation: Genetics Education and Health Research, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria 3052, Australia; Centre for Developmental Disability Health Victoria, Monash University, Clayton, Victoria 3800, Australia; Fragile X Alliance Inc., Clinic and Resource Centre, 263 Glen Eira Road, North Caulfield, Victoria 3161, Australia.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cohen
authors.affiliation: Department of Developmental Disability Neuropsychiatry and Centre for Health Brain Ageing, School of Psychiatry, University of New South Wales, Sydney 2052, Australia.
authors.forename: Julian N
authors.initials: JN
authors.lastname: Trollor
authors.affiliation: School of Psychiatry and Psychology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800, Australia. Electronic address: joanne.fielding@monash.edu.
authors.forename: Joanne
authors.initials: J
authors.lastname: Fielding
mesh_terms: D000328:Adult; D056344:Executive Function; D005133:Eye Movements; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000235:genetics* / Q000523:psychology*; D006801:Humans; D007266:Inhibition, Psychological; D008875:Middle Aged; D009483:Neuropsychological Tests; D055815:Young Adult
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1
keywords: Eye tracking; FMR1; FXS; Fragile X syndrome; Premutation carrier; Response inhibition; Saccade