DICER1 and Huntington disease: Dicer also functions in pathogenesis from triplet repeat expansion disorders, including DM1, HD, FXTAS and SCA1, where it cleaves the triplet repeat dsRNA hairpin structures into short (∼21 nucleotide) CNG dsRNAs (Krol et al., 2007; Bañez-Coronel et al., 2012; Kelley et al., 2012).