In Huntington’s disease (HD), a neurodegenerative disorder inherited in an autosomal dominant pattern caused by a mutation in the huntingtin (HTT) gene, the intranasal delivery of chitosan-based nanoparticles containing anti-HTT siRNA decreased HTT mRNA levels by more than 50% in YAC128 transgenic mice [54,105]. Here, HTT is linked to juvenile Huntington disease.