Huntington's disease is an autosomal dominant slowly degenerative apoptotic condition in CNS, in particular in striatum. It is characterized by involuntary movements; in particular chorea, personality changes and subcortical dementia. About 250 persons are diagnosed in Norway with the condition at any time, most are diagnosed between 35 and 55 years but onset before 20 years of age can be seen and diagnosis in later life is not rare. The average duration is about 15 years from diagnosis to death, but it can be considerably longer. Signs, symptoms and therapeutic challenges are mentioned in addition to molecular and clinical genetic aspects, in particular pre-symptomatic and prenatal diagnosis.