In this study, we designed a series of LNA-based splice-switching oligonucleotides (SSOs) targeting human SMN2 ISS-N1 in intron 7, and examined their ability to induce exon inclusion. We demonstrated that five LNA/DNA mixmers we designed efficiently induce exon inclusion and recover the expression of SMN protein in type I SMA patient fibroblasts (Figs 3 and 4). A single mismatch significantly decreased the ability to induce exon inclusion, suggesting that these LNA/DNA mixmers are highly specific to the targeted sequence (Fig. 5). This is the first report showing that LNA/DNA mixmers induce efficient exon inclusion. It might, therefore, be an attractive therapeutic strategy to treat SMA.