 Huntingtons disease HD is a genetic disease characterized by changes in movement and behavior. To date, little research has been done on individuals who are at risk for developing the disease. PHAROS is an observational study designed to monitor people who are at risk for developing HD, and to survey their attitudes and beliefs about their at-risk status. Investigators hope this study will help answer some important questions about HD, such as: 1. What are the earliest signs of HD and when do they start? 2. How accurate are the measures that physicians use in detecting the onset of HD? 3. What factors influence the age at which a person carrying the HD gene develops the illness? and 4. In a group of people at risk for HD, how many will develop signs of the illness over a minimum three-year period of observation? 