This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All of the following are neurologic channelopathies except - 
Select and explain. 
A. Hypokalemic periodic paralysis, B. Episodic ataxias, C. Familial hemiplegic migraine, D. Huntington's disease
D: Huntington's disease
Answer: D: Huntington's disease 
Explanation: None