CACNA1A and spinocerebellar ataxia type 6: Mutations in the CACNA1A gene that encodes the pore-forming CaV2.1 α1 subunit cause three neurological disorders: familial hemiplegic migraine type 1 (FHM1), spinocerebellar ataxia type 6 (SCA6) and Episodic ataxia 2 (EA2) (Pietrobon, 2010).