Cacna1a knockout mice, and the naturally occurring cacna1a mutant mouse tottering, have been widely studied and show absence epilepsy, ataxia and paroxysmal dyskinesia, with progressive loss of cerebellar Purkinje cells (Fletcher et al., 1996, Fletcher et al., 2001, Shirley et al., 2008). The gene discussed is CACNA1A; the disease is cerebellar ataxia.