This neurodegenerative disease is caused by an expansion of a cytosine-adenine-guanine (CAG) repeat tract in exon 10 of the Ataxin-3 (ATXN3) gene located in chromosome 14q32.1, which encodes an abnormally long polyglutamine (polyQ) segment in the ATXN3 protein, making it prone to self-assembly, and to form aggregates that are toxic to neurons [2,3,4]. This evidence concerns the gene ATXN3 and neurodegenerative disease.