Identification and allele-specific silencing of the mutant huntingtin allele in Huntington's disease patient-derived fibroblasts

Hum Gene Ther. 2008 Jul;19(7):710-9. doi: 10.1089/hum.2007.116.


Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by the expression of mutant huntingtin protein (Htt). Suppression of Htt expression, using RNA interference, might be an effective therapy. However, if reduction of wild-type protein is not well tolerated in the brain, it may be necessary to suppress just the product of the mutant allele. We present a small interfering RNA (siRNA) that selectively reduces the endogenous mRNA for a heterozygous HD donor's pathogenic allele by approximately 80% by specifically targeting a single-nucleotide polymorphism (SNP) located several thousand bases downstream from the disease-causing mutation. In addition, we show selective suppression of endogenous mutant Htt protein, using this siRNA. We further present a method, using just a heterozygous patient's own mRNA, to determine which SNP variants correspond to the mutant allele. The method may be useful in any disorder in which a targeted SNP is far downstream from the pathogenic mutation. These results indicate that allele-specific treatment for Huntington's disease may be clinically feasible and practical.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles
  • Cells, Cultured
  • DNA Primers
  • Female
  • Fibroblasts / metabolism
  • Genetic Therapy / methods*
  • Humans
  • Huntingtin Protein
  • Huntington Disease* / genetics
  • Huntington Disease* / therapy
  • Middle Aged
  • Mutant Proteins / genetics*
  • Mutant Proteins / metabolism
  • Mutation
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Polymerase Chain Reaction
  • Polymorphism, Single Nucleotide
  • RNA Interference*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering* / genetics
  • RNA, Small Interfering* / metabolism


  • DNA Primers
  • HTT protein, human
  • Huntingtin Protein
  • Mutant Proteins
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • RNA, Small Interfering