Which disorder involves the inability to control involuntary movements?

Huntington's Disease is characterized by the progressive degeneration of nerve cells in the brain, leading to a variety of motor, cognitive, and psychiatric symptoms. One of the hallmark features of this disorder is the presence of involuntary movements, often described as chorea, which includes irregular, unpredictable movements of the limbs and face. This inability to control these movements is a direct consequence of the damage to specific areas of the brain responsible for movement coordination and control.

In contrast, while Cerebral Palsy does involve motor control issues, these are often due to brain injury or malformations that affect muscle tone and voluntary movements rather than presenting as involuntary movements. Down's Syndrome is a genetic condition associated with various developmental and physical challenges, but it does not specifically involve the inability to control involuntary movements. Developmental Disability is a broad term that includes various conditions affecting daily functioning, but it does not specifically refer to the involuntary movements seen in Huntington's Disease. Thus, the focus on involuntary movements makes Huntington's Disease the most appropriate choice for this question.