Toward therapy for DYT1 dystonia: Allele-specific silencing of mutant TorsinA

Authors

  • Pedro Gonzalez-Alegre MD,

    1. Department of Neurology, University of Iowa College of Medicine, Iowa City, IA
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  • Victor M. Miller MPH,

    1. Department of Neurology, University of Iowa College of Medicine, Iowa City, IA
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  • Beverly L. Davidson PhD,

    1. Department of Neurology, University of Iowa College of Medicine, Iowa City, IA
    2. Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, IA
    3. Departments of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA
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  • Henry L. Paulson MD, PhD

    Corresponding author
    1. Department of Neurology, University of Iowa College of Medicine, Iowa City, IA
    • Department of Neurology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242-1101
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Abstract

A three-nucleotide (GAG) deletion in the TOR1A gene is the most common cause of inherited dystonia, DYT1. Because the mutant protein, TorsinA (TA), is thought to act in a dominant manner to cause disease, inhibiting expression from the mutant gene represents a potentially powerful therapeutic strategy. In an effort to develop therapy for this disease, we tested whether small interfering RNA (siRNA) could selectively silence expression of mutant TA. Exploiting the three–base pair difference between wild-type and mutant alleles, we designed siRNAs to silence expression of mutant, wild-type, or both forms of TA. In transfected cells, siRNA successfully suppressed wild-type or mutant TA in an allele-specific manner: for example, mutant-specific siRNA reduced the levels of mutant TA to less than 1% of controls with minimal effect on wild-type TA expression. In cells expressing both alleles, thus simulating the heterozygous state, siRNA-mediated suppression remained robust and allele specific. Our siRNA studies demonstrate allele-specific targeting of a dominant neurogenetic disease gene and suggest the broad therapeutic potential of siRNA for DYT1 dystonia and other dominantly inherited neurological diseases. Ann Neurol 2003;53:781–787

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