At the neuropathological level, HD is characterized by neuronal degeneration in the striatum and the cortex (Reiner et al., 1988; Rosas et al., 2003) and the formation and accumulation of nuclear inclusions composed of mutant Htt (polyQ repeat ≥36) aggregates and other proteins (DiFiglia et al., 1997; Hodgson et al., 1999). This evidence concerns the gene HTT and Huntington disease.