Update on mutations of precursor mRNA splicing factor genes linked to retinitis pigmentosa

Retinitis pigmentosa (RP), one of the common forms of hereditary retinal dystrophies (HRD), is typified by significant genetic heterogeneities.Executed by the spliceosome, precursor mRNA (pre-mRNA) splicing is a highly regulated process by which introns are removed and exons are ligated together.To date, more than 80 genes have been involved in RP etiology.Specially, 8 of these genes (PRPF3, PRPF8, PRPF31, PRPF6, PRPF4, SNRNP200, RP9 and DHX38) encode proteins essential for pre-mRNA splicing and are expressed ubiquitously.However, mutations of these RP causative pre-mRNA splicing genes exclusively result in only retinal phenotypes, and the mechanism remains unknown.In this review, we recapitulate splicing process, summarize the mutations identified in pre-mRNA splicing genes related to RP and discuss conceivable hypothesis explaining for the consequent retina-specific phenotypes.