Enroll-HD is a long-term international study for people with Huntington's Disease (HD). HD is a condition where nerve cells in the brain break down over time. This study collects health information and blood samples from people with HD, people at risk of getting HD, and those without HD. The study has over 30,000 participants and no end date, meaning it continues indefinitely. The data helps researchers understand HD better and develop new treatments. There are over 150 places in 23 countries where participants can join.

Eligibility: People who can join include those who have the HD gene, those who do not, and family members. Some people in the study might have symptoms of HD, while others might not. People with other major brain disorders cannot join.

• **Length of Study:** Ongoing, no end date.
• **Visits Needed:** Annual assessments.
• **Eligibility:** Includes individuals with HD, at risk, and controls without HD.

To learn more, visit Enroll-HD.