In line with the cerebellar expression of PLEKHG4, using positional cloning, Ishikawa and colleagues [178] have demonstrated that single nucleotide substitution in the 5′ untranslated region (UTR) of the PLEKHG4 gene is associated with autosomal dominant cerebellar ataxia (ADCA), a group of heterogeneous neurodegenerative disorders. Here, PLEKHG4 is linked to autosomal dominant cerebellar ataxia.