Spinocerebellar ataxia type 2 (SCA2) is an inherited disorder caused by polyglutamine (polyQ) tract expansions secondary to mutations of the ATXN2 gene (coding for the Ataxin-2 protein); these polyQ expansions are encoded at the DNA level in ATXN2 by trinucleotide CAG repeats [65]. This evidence concerns the gene ATXN2 and spinocerebellar ataxia type 2.