SOD1 and juvenile Huntington disease: Motivated by the desire to additionally test the ASO chemistry now in clinical trials for Huntington's disease and Amyotrophic lateral sclerosis (ALS) with SOD1 mutations (25,55), we undertook optimization at the binding sites of active ASOs 1 and 2 to design and synthesize a set of ASOs with mixed PS/PO backbones and a 10-base deoxynucleotide gap flanked on each end with 2’O-methoxyethyl (MOE) modified nucleotides (Table 1, Figure 1B).