PRPF31 and retinitis pigmentosa: A prime example is mutations in ubiquitously expressed members of the U4/U6-U5 tri-snRNP particle (PRPF31, PRPF3, PRPF4, PRPF6, PRPF8) and splice-complex proteins (SNRNP200 and PAP1), which are the second-most frequent cause of autosomal dominant forms of retinitis pigmentosa (adRP) after mutations in rhodopsin1–3.