Which genetic disorder is known for choreiform movements and personality changes?

Huntington's disease is characterized by choreiform movements, which are involuntary, irregular, and brief movements that are typically dance-like. This neurological disorder is also associated with progressive personality changes, such as mood swings, irritability, and eventual cognitive decline. The underlying genetic basis of Huntington's disease is a trinucleotide repeat expansion (CAG repeats) in the HTT gene, leading to the production of an abnormal form of the huntingtin protein, which ultimately causes neurodegeneration, particularly in areas of the brain responsible for movement and behavior.

In contrast, Parkinson’s disease primarily presents with resting tremors, rigidity, and bradykinesia, rather than chorea. Myasthenia gravis is an autoimmune disorder characterized by muscle weakness and fatigue, rather than movement disorders or personality changes. Alzheimer's disease involves cognitive decline and memory impairment, primarily affecting the temporal and parietal lobes, but it does not typically present with choreiform movements. Thus, the distinctive combination of choreiform movements and personality changes highlights Huntington's disease as the correct answer.