Loss-of-function mutations in the human CaV2.1 subunit-encoding CACNA1A gene are linked to the autosomal dominant cerebellar disease episodic ataxia type 2 (EA2), manifesting as paroxysmal attacks of ataxia and nystagmus [36, 37, 63, 67, 71]. The gene discussed is CACNA1A; the disease is pathologic nystagmus.