Prp31 is a component of the U4/U6-U5 snRNP complex that is involved in pre-mRNA splicing []. It is required for U4/U6.U5 tri-snRNP formation [, ]. Defects in PRPF31 are the cause of retinitis pigmentosa type 11 (RP11). RP leads to degeneration of retinal photoreceptor cells [, , ].