Different mutations of the CACNA1A genes, which encode the immunogenic alpha-1A VGCC subunit (Cav2.1), can produce the autosomal dominant SCA type 6, episodic ataxia type 2 (EA2) or familial hemiplegic migraine 1 (FHM1). Here, CACNA1A is linked to Familial paroxysmal ataxia.