Intro Huntington's disease (HD) patients suffer from motor, cognitive and behavioral impairments, with heterogeneous phenotypes and variable time course. This leads to a high variance of HD markers, none of which is currently sensitive enough to 1) measure disease progression from small cohort data, 2) predict disease entry in carriers of the HD mutation (during the prodromal phase or in patients considered asymptomatic: pre-HD patients), and 3) measure a significant evolution of the state of pre-HD patients over a time window compatible with the realization of clinical trials (about 2/3 years). Moreover, the markers of HD do not allow a fine stratification of the patients. Hypothesis/Objective Our objectives are 1) to evaluate the sensitivity of new markers and assessment tools for symptomatic (HD) and presymptomatic (pre-HD) patients, 2) to define a model of disease progression, and 3) to establish an enrichment strategy to improve patient selection for future therapeutic trials. Method We will evaluate newly developed cognitive tests, multimodal imaging techniques, biological markers and use innovative statistical approaches. We will follow 60 patients with the mutation responsible for MH (40 presymptomatic pre-MH patients, 20 symptomatic MH patients) and 20 healthy volunteers (controls) over a 24-month period.