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Ethnic differences in the expression of neurodegenerative disease: Machado-Joseph disease in Africans and Caucasians

Authors

  • S.H. Subramony MD,

    1. University of Mississippi Medical Center, Neurology Department, Jackson, Mississippi, USA
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  • Dena Hernandez BS,

    1. Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
    2. Laboratory of Neurogenetics, NIA/NIH, Rockville Pike, Bethesda, Maryland, USA
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  • Amanda Adam BS,

    1. Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
    2. Laboratory of Neurogenetics, NINDS/NIH, Rockville Pike, Bethesda, Maryland, USA
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  • Stephanie Smith-Jefferson MS,

    1. Division of Medical Genetics, Department of Preventive Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
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  • Jennifer Hussey BS,

    1. Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
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  • Katrina Gwinn-Hardy PhD,

    1. Laboratory of Neurogenetics, NINDS/NIH, Rockville Pike, Bethesda, Maryland, USA
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  • Timothy Lynch MD,

    1. Department of Neurology, Columbia University, New York, USA
    2. Department of Neurology, Mater Misericordiae Hospital, Dublin, Ireland
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  • Olga McDaniel MD,

    1. University of Mississippi Medical Center, Surgery Department, Jackson, Mississippi, USA
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  • John Hardy MD,

    Corresponding author
    1. Laboratory of Neurogenetics, NIA/NIH, Rockville Pike, Bethesda, Maryland, USA
    2. Department of Neurology, Reta Lila Weston Institute of Neurological Studies Royal Free And University College London Medical School London, United Kingdom
    • Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224
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  • Matt Farrer PhD,

    1. Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
    2. Laboratory of Neurogenetics, NIA/NIH, Rockville Pike, Bethesda, Maryland, USA
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  • Andrew Singleton PhD

    1. Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
    2. Laboratory of Neurogenetics, NIA/NIH, Rockville Pike, Bethesda, Maryland, USA
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Abstract

We describe several families of African origin with SCA3/Machado-Joseph disease gene expansions. In these cases, the phenotype ranges from ataxia with parkinsonian signs to a syndrome clinically almost indistinguishable from idiopathic, L-dopa–responsive Parkinson's disease. In contrast, these parkinsonian phenotypes are rare in those of European descent. Haplotype analysis shows that these African families do not share a common founder, thus a cis-acting element in the promoter is unlikely to be responsible these unusual presentations. We suggest that trans-acting factors are responsible for the variable phenotype and discuss the implications of diseases showing racially different expressivities. © 2002 Movement Disorder Society

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