Spinocerebellar ataxias (SCA) are rare genetic diseases that affect the brain, causing problems with balance, coordination, and speech. This study focuses on types 1, 2, 3, and 6, which are slowly worsening over time. Researchers aim to understand how the disease progresses and if other genes might influence its behavior. Around 800 participants from across the USA will join, with checkups every 6 or 12 months. During the study, a small blood sample (15 milliliters) will be taken to study your DNA and possibly stored in a research bank. Your identity will remain private, and you can choose to remove your sample later if desired. Participation in the genetic study or tissue repository is optional. You'll also complete tests like questionnaires, movement tests, and physical exams. To join, you must have a confirmed SCA diagnosis, be willing to participate, and be at least 6 years old. You cannot join if your condition is linked to other specific genetic issues or if you don't want to take part.

• Visits every 6 or 12 months.
• Blood sample needed, but privacy is protected.
• Optional participation in genetic studies.