The CAG repeat is translated into an expanded polyglutamine (polyQ) track in the ATXN1 protein [2], which places SCA1 into the family of polyglutamine diseases that also includes SCA 2, 3, 6, 7, 17, Kennedy disease, Huntington’s disease, and dentatorubropallidoluysian atrophy [3]. Here, ATXN1 is linked to Huntington disease.