[Huntington's disease and Sydenham's chorea].

Huntington's disease was an important example for discussing the problem of predictive genetic testing. Like other movement disorders, it includes non-motor symptoms and a prodromal phase. As a rapidly progressive monogenetic disease, it is an important model disease for the study of neurodegenerative pathomechanisms and one of the first movement disorders for which causal therapies seem to be reachable.