Huntington disease

Huntington disease (HD) is a rare neurodegenerative disorder of the central nervous system. HD is an autosomal dominant disorder due to a mutation resulting in an increased number of triplicate cytosine-adenine-guanine repeats on chromosome 4. The manifestations include chorea, dementia and personality changes. In the Westphal variant dystonia and parkinsonism are prominent. Neuroimaging reveals caudate atrophy. A genetic test is available and may facilitate presymptomatic detection.