Abstract
Huntington's disease (HD) is an autosomal dominantly inherited neuropsychiatric degenerative condition with a fatal prognosis. It is caused by mutation the expansion of CAG (containing cytosine-adenine-guanine) triplet repeats 40 and more at the short arm of 4th chromosome.
The main clinical features are motor impairment (especially choreatic dyskinesias and the impairment of voluntary movements), progressive cognitive deterioration and personality changes. The product of the mutation is an aberrant protein known as huntingtin with an enlarged polyglutamine stretch.
The prevalence of HD is approximately 1: 10-15,000. The typical onset of HD is in the 4th decade with a minority of cases starting in childhood or adolescence (juvenile HD) or in patients over 65 years of age (late-onset of HD).
The initial symptoms are usually non-specific: behavioural changes, personality and affective disorders. As HD progresses, cognitive disturbance appears, leading to severe dementia.