SCA6, the third disorder associated with mutations in the CACNA1A gene, is characterized by cerebellar ataxia and progressive cerebellar degeneration, and is caused by CAG repeat expansions in the CACNA1A gene, resulting in an aberrant polyglutamine chain in the C-terminus of Cav2.1 channels (Watase et al., 2008; Zhuchenko et al., 1997). Here, CACNA1A is linked to cerebellar ataxia.