The UBC site recruited 90 subjects including 30 control subjects, 30 asymptomatic pre-manifest HD gene carriers and 30 subjects with early symptoms of HD (stage 1 or 2). All subjects were assessed using the TRACK-HD battery at baseline, 1 year, 2 years, and 3 years. Following the fourth visit (3 year assessment), the TRACK-HD study will be completed, and the 30 subjects with early symptoms of HD will be invited to enroll in the MITIGATE-HD Study.