BBS1 and Bardet-Biedl syndrome: Two remarkable examples of complex SVs as a cause of IRD are SVA retrotransposon insertions in MFSD8- and BBS1-associated disease, of which the first SV served as a target for antisense oligonucleotide treatment, and the second appears to be a frequent cause of Bardet–Biedl syndrome (Kim et al., 2019; Delvallée et al., 2020).