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Action Tremor and Cognitive Functioning in Male Carriers of Fragile X


Funded by:  National Institute of Neurological Disorders and Stroke, National Institutes of Health
Project Period: September 2003 - June 2008

The objectives of the study are to define the clinical features of fragile X-associated tremor/ataxia syndrome (FXTAS) and to examine the progression of the disorder over a three-year period. The study is designed to assess cognitive, neurological, and functional impairment in men with FXTAS and to investigate changes in brain structure associated with the disorder.

Three groups of men age 40 and older will be involved in the study: (1) men with the fragile X premutation and symptoms of FXTAS; (2) men who are carriers of the fragile X premutation, but who have not developed FXTAS; and (3) healthy men who do not have the fragile X premutation. (Forty men will participate in each of the groups, which will be matched on age and education.) All participants will undergo a complete neurological examination by a neurologist specializing in movement disorders, comprehensive cognitive testing, an assessment of functional ability, magnetic resonance imaging (MRI) of the brain, and genetic testing. Data will be collected at an initial visit and again 18 and 36 months later.

The study is based at the University of Colorado Denver in Denver, Colorado. Participants also are being recruited and evaluated at the M.I.N.D. Institute at the University of California, Davis, Medical Center in Sacramento, California.

Potential Impact of the Research
The results of this study will provide important information about the clinical features of FXTAS. Investigators will gain a clearer understanding of (1) the types of neurological, cognitive, and functional impairments that men with FXTAS experience; (2) the progression of these impairments over time; and (3) the changes in brain structure that accompany the disorder. The knowledge gained as part of this study will be of substantial clinical importance for the diagnosis, management, and appropriate treatment of this newly identified and often misdiagnosed disorder.

Project Staff
Principal Investigator of the Study:  Jim Grigsby, PhD
Principal Investigator at the M.I.N.D. Institute:  Randi Hagerman, MD
Project Manager:  Rachael Bennett, MA

Recruitment Information
Enrollment of participants in this study currently is underway. We are recruiting men age 40 and older who are carriers of the fragile X premutation as well as healthy men who are neither carriers of the premutation nor affected by fragile X syndrome. Participants are compensated for their time. If you would like further information or think you might like to participate in this study, please contact Rachael Bennett by phone at (303) 724-2476 or by email at