In our study, we have identified a pathogenic splice defect caused by a branchpoint variant in BBS1 gene in four unrelated individuals with non-syndromic retinitis pigmentosa. Splicing is the process in which the pre-mRNA is transformed into mature mRNA by removing the introns and joining the exons. The branchpoint nucleotide ‘A’, plays a crucial step at the 5’ donor splice site and ensures accurate splicing. By using an in vitro midigene splice assay, we showed that compared to the wildtype, the c.592-21A>T variant led to a complex splicing effect with partial or full exon 8 skipping in BBS1. (By Susanne Roosing, https://jmg.bmj.com/content/early/2021/04/27/jmedgenet-2020-107626 )