Heterozygous mutations of the brain spectrin gene SPTBN2, which encodes the protein β‐III‐spectrin, are one cause of spinocerebellar ataxia type 5 (SCA5) (Ikeda et al., 2006), an autosomal dominant neurodegenerative disease. The gene discussed is SPTBN2; the disease is spinocerebellar ataxia type 5.