NEW FEDERALLY FUNDED RESEARCH PROJECT ON ATAXIA Submitted by: Christopher M. Gomez, M.D., Ph.D umataxrc@tc.umn.edu Title: Genotype-Phenotype Correlations in Autosomal Dominant Ataxia Principal Investigator: Christopher M. Gomez, M.D., Ph.D. Co-Principal Investigator: John H. Anderson, M.D., Ph.D. Research Site: University of Minnesota Ataxia Research Center Project Dates: July 1, 1998 - June 30, 2003 Purpose of Project: To improve understanding of the neuroanatomy, neurophysiology, temporal progression, and functional differences between genetically distinct forms of autosomal dominant cerebellar ataxia and hereditary episodic ataxia. Description of Project: The autosomal dominant spinocerebellar ataxias (SCAs) and episodic ataxias (EAs) are a group of adult- and juvenile-onset neurodegenerative diseases characterized by progressive or intermittent dysarthria and incoordination due to degeneration of the cerebellum and brainstem. Advances in the genetic understanding of these diseases have established that, despite similar clinical presentations, there are at least 9 genetically distinct subtypes, SCA1-SCA7, EA-1 and EA-2. Clinical observations have suggested that eye movements and postural stability are universally but differentially impaired in the SCAs, presumably due to regional differences in brainstem and cerebellar involvement in the disease. In this project we address the question of whether specific patterns of eye movement abnormalities and postural instability characterize genetically-defined SCAs. The goal is to provide a more detailed understanding of oculomotor and vestibular function in SCA that will allow us to identify common abnormalities useful for comparative scoring among kindreds and also abnormalities that are unique to a given SCA subtype. These findings may also indicate specific brain regions that are uniquely impaired in certain forms of ataxia. To pursue the laboratory studies, we will take advantage of a unique database at the University of Minnesota and recent advances in both the genetics of autosomal dominant ataxia and in the technology for recording and analyzing eye movements and the dynamic control of posture. These studies may identify diagnostic features for some SCA types and provide valuable information about selective vulnerability of CNS neurons and the pathogenesis of CAG repeat diseases. They also may identify traits common to all patients with ataxia that will be useful as quantitative measures for therapeutic trials. These studies will test the hypothesis that sensitive measures of eye movements and balance can be used to detect and quantify ataxia from its earliest stages. Inquiries: Those interested in participating should respond by e-mail (preferable), fax or postal service. All respondents will be sent a questionaire to be completed and should be prepared to provide additional information on previous neurological and genetic testing.  Email: umataxrc@tc.umn.edu Fax: 612-626-2639 Postal address: University of Minnesota Ataxia Research Center Box 295 UMHC 420 Delaware St Minneapolis, MN 55455 USA