Huntington disease (HD) is a progressive brain disorder caused by a defective gene. It affects the basal ganglia, a part of the brain that is important for movement, emotion, and cognition. The disease is characterized by a broad range of motor, cognitive, and psychiatric symptoms which worsen over time.

HD is a hereditary disease, meaning it is passed down through families. The onset of symptoms typically occurs in mid-adulthood, but juvenile forms of the disease can start earlier. Unfortunately, there is no cure for Huntington Disease, and the condition gradually worsens, leading to severe physical and mental disability.