CACNA1A and episodic ataxia type 2: 1997; Mantuano et al. 2003; Romaniello et al. 2010). Nonsense mutations (Ophoff et al. 1996), deletions (Riant et al. 2008; Labrum et al. 2009), and missense mutations in CACNA1A gene have all been found to lead to loss‐of‐function of recombinant human CaV2.1 channels in heterologous expression systems found to cause EA2.