Huntington's Disease is an autosomal dominant disease characterized by degeneration of striatal neurons, particularly of the caudate nucleus, leading to dementia and movement disorders.

The mutant huntington protein coded by the HD gene accumulates within intranuclear inclusions.

The defect causes a part of DNA, called CAG repeat, to occur in more times than it is supposed to. Normally, this section of DNA is repeated 10 to 35 times. But in persons with Huntington's disease, it is repeated 36 to 120 times.

Huntington's chorea is hereditary.

Initially, there is motor dysfunction and dementia, caused by the loss of neurons of the CNS that produce the neurotransmitter, GABA.

The advent of dementia is thought to be related to the loss of acetylcholine-secreting cells.

Patients show degenerative changes in the basal ganglia structures. They exhibit severely shrunken brain and enlarged ventricles.

They caudate and putamen brain structures are particularly affected as they shrink up to half their normal size.

The symptoms of the disease are caused by a significant reduction (volume and activity) of two principal neurotransmitters, acetylcholine and GABA, in turn affecting the activity of the neurotransmitter dopamine, which becomes hyperactive.
- Can be caused by a lesion of the striatum.
- Huntington's patients typically have chorea-like movements.