BBS1 and Bardet-Biedl syndrome: This is the case of a combined treatment for Bardet–Biedl syndrome recently developed by Breuel and colleagues [64] in which a modified U1 snRNA (to correct the exon skipping) and ASOs (to block intron retention) were used in an attempt to correct the effect of a mutation in the last base of exon 5 of the BBS1 gene (c.479G>A), which leads to both exon 5 skipping and intron 5 retention.