In spinocerebellar ataxia type 6 (SCA6), an autosomal-dominant neurodegenerative disease caused by a small expansion of CAG repeat encoding polyglutamine (polyQ) in the gene for α1A voltage-dependent calcium channel (Cav2.1) and characterized by Purkinje cell neuronal loss, the BDNF mRNA levels and BDNF protein expression in the SCA6 cerebellum significantly reduced, whilst numerous BDNF-immunoreactive granules were found in the dendrites of SCA6 Purkinje cells [136]. This evidence concerns the gene BDNF and spinocerebellar ataxia type 6.