Huntington’s disease (HD) is a progressive autosomal dominant neurodegenerative disorder [179,180] caused by a trinucleotide CAG repeats in exon-1 of the huntingtin gene (HTT) on the fourth chromosome (4p16.3) [181], resulting in the expression of a polyglutamine-expanded mutant Huntington protein (mHTT) at the amino-terminal end of the protein [182]. Here, HTT is linked to juvenile Huntington disease.