Anatomy · Embryology and Genetics

Autosomal dominant inheritance

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  • Autosomal dominant inheritance: disease pattern needing only one defective copy of the gene, from either parent, e.g. Huntington's disease.

Huntington's Disease: Genetic Basis and Pathology

  • Huntington's disease (HD): fatal neurodegenerative disorder caused by an autosomal dominant mutation of the HD gene, located on the short arm of chromosome 4.
  • The mutant HD gene causes death of neurons in the caudate nucleus and putamen, producing Huntington's chorea.
  • Death follows about 5 to 10 years after symptoms first appear.

Clinical

  • Huntington's chorea: involuntary chorea (dance-like) movements of the limbs, from the underlying neuronal loss in the caudate nucleus and putamen.
  • Further features: mood disturbances, and swift grimaces with sudden movements of the head.
  • Progressive loss of mental activity also occurs.

High Yield

  • Autosomal dominant disease needs only one defective gene copy, from either parent, e.g. Huntington's disease.
  • HD gene: short arm of chromosome 4; mutant gene kills neurons in caudate nucleus and putamen.
  • Death follows 5 to 10 years after symptom onset.
  • Clinical features: chorea, mood disturbances, grimaces, progressive loss of mental activity.