title: A cognitive characterization of dyscalculia in Turner syndrome.
abstract: Current theories of number processing postulate that the human abilities for arithmetic are based on cerebral circuits that are partially laid down under genetic control and later modified by schooling and education. This view predicts the existence of genetic diseases that interfere specifically with components of the number system. Here, we investigate whether Turner syndrome (TS) corresponds to this definition. TS is a genetic disorder which affects one woman in 2500 and is characterized by partial or complete absence of one X chromosome. In addition to well-characterized physical and hormonal dysfunction, TS patients exhibit cognitive deficits including dyscalculia. We tested 12 women with Turner syndrome and 13 control subjects on a cognitive battery including arithmetical tests (addition, subtraction, multiplication, division) as well as tests of the understanding of numerosity and quantity (cognitive estimation, estimation, comparison, bisection, subitizing/counting). Impairments were observed in cognitive estimation, subitizing, and calculation. We examine whether these deficits can be attributed to a single source, and discuss the possible implications of hormonal and genetic factors in the neuropsychological profile of TS patients.
authors.affiliation: INSERM Unit 562 Cognitive Neuroimaging, Service Hospitalier Frédéric Joliot, CEA/DRM/DSV, 4 Place du général Leclerc, 91401 Orsay Cedex, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Bruandet
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molko
authors.forename: Laurent
authors.initials: L
authors.lastname: Cohen
authors.forename: Stanislas
authors.initials: S
authors.lastname: Dehaene
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000150:complications* / Q000235:genetics; D008433:Mathematics; D011340:Problem Solving / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D014424:Turner Syndrome / Q000150:complications* / Q000235:genetics