ATXN7 and spinocerebellar ataxia 7: The mutation causing SCA7 is an abnormal expansion of a CAG triplet repeat located in the ATXN7 gene coding region, on the chromosomal region 3p12-21.1 [8]; the expanded CAG repeats lead the translation of ataxin-7 carrying an abnormally large glutamine-rich tract (polyQ).