Huntington’s Disease

  • Progressive neurodegenerative disease
  • Autosomal Dominence
  • So if theres one parent suffering there’s a 50% chance of their offspring suffering
  • Symptoms develop in middle age
  • unsteady gait –> jerky movements –> behavioural change –> progressive dementia


Huntington’s Disease was previously called Huntington’s Chorea – but it’s much more than just the chorea (shaky movements).

It’s the most common inherited neurodegerative disorder.

Onset of symptoms are typically between age 30 and age 50 (although symptoms of Juvenille Huntington’s disease can occur before the age of 20).

There is relentless progression of neurological degeneration with steady increase of choreic movements and dementia. Patients usually die from intercurrent illness such as pneumonia but suicide is the second most common cause.

Signs and Symptoms

  • Initally: fidgeting with fleeting facial movements
  • clumsiness
  • apathy
  • self neglect
  • personality change
  • Behavioural problems – these may lead to family conflict or relationship breakdown before the symptoms
  • Almost everyone eventually develops chorea

Chorea = Jerky, random, uncontrolled movements



The disease is autosomal dominant: an affected individual inherits one copy of the faulty gene from and affected parent.

Each child of a patient with Huntington’s has a 50% chance of inheriting the condition.

The huntingtons disease gene (HTT) is located on the short arm of chromosome 4.

This gene codes for the cytoplasmic protein Huntingtin.