For instance, the ATXN3 gene usually contains 13–41 CAG repeats [3]; more than 55 CAG repeats in the ATXN3 gene are pathogenic and can cause spinocerebellar ataxia type 3 (SCA3), which is a condition characterized by progressive problems with movement [4]. The gene discussed is ATXN3; the disease is Spinocerebellar ataxia type 3.