Consistently, germline transmission studies in SCA3 have also failed to reveal obvious parental allele length effects (Maciel et al. 1995; Durr et al. 1996; Martins et al. 2008; Souza et al. 2016) that are characteristic of SCA1, SCA2, SCA7, HD and most other repeat expansion disorders (Depienne and Mandel 2021). This evidence concerns the gene ATXN3 and Huntington disease.