All of the following are neurologic channelopathies, except :

Answer is D (Huntington's disease): Huntington's disease is not a channelopathy. Huntington's disease is an autosomal dominant disorder caused by mutations in the Huntington's gene on the sho arm of chromosome 4, specifically in an expanding and unstable polyglutamine repeat sequence (CAG). The gene encodes for protein 'Huntington' which is present in all neurons. Channelopathies: Refers to a group of disorders caused by affection of muscle membrane excitability. Neurologic Channelopathies : Category Disorder Channel type Ataxias Episodic ataxia -1 Episodic ataxia - 2 Spinocerebellar ataxia - 6 K Ca Ca Migraine Familial hemiplegic migraine Ca Epilepsy Benign neonatal familial convulsions Generalised epilepsy with febrile convulsions plus K Na Periodic paralysis Hyperkalemic periodic paralysis Hypokalemic periodic paralysis Na Ca Myotonia Myotonia congenital Paramyotonia congenital Cl Na Deafness Jorvell and Lange-Nielsen syndrome (deafness, prolonged QT interval, and arrhythmia) Autosomal dominant progressive deafness K K