Turner Syndrome Research Today is a free monthly online journal that collates and summarizes the latest research about Turner Syndrome, including details on symptoms, causes, chromosomes, prognosis.

Ocular motor indicators of executive dysfunction in fragile X and Turner syndromes.

Lasker AG, Mazzocco MM, Zee DS

Department of Neurology, Suite 2210, Pathology Building, The Johns Hopkins School of Medicine, 601 N. Broadway, Baltimore, MD 21287-6921, USA. alasker@dizzy.med.jhu.edu

Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner syndrome, and 40 females with neither disorder who comprised the comparison group. Group differences emerged for both the fragile X and Turner syndrome groups, each relative to the comparison group: Females with fragile X had deficits in generating memory-guided saccades, predictive saccades, and saccades made in the overlap condition of a gap/overlap task. Females with Turner syndrome showed deficits in generating memory-guided saccades, but not during either the predictive saccade or gap/overlap task. Females with Turner syndrome, but not females with fragile X, showed deficits in visually guided saccades and anti-saccades. These findings indicate that different brain regions are affected in the two disorders, and suggest that different pathways lead to the similar cognitive phenotypes described for fragile X and Turner syndromes.

Published 13 March 2007 in Brain Cogn, 63(3): 203-20.
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