Dominant retinitis pigmentosa phenotype associated with a new mutation in the splicing factor PRPF31

Autosomal dominant retinitis pigmentosa results from mutations in 14 known proteins, and at least two further loci have been highlighted by genetic linkage in families (reviewed by the RetNet website; http://www.sph.uth.tmc.edu/Retnet/). The known genes include those encoding components of the phototransduction cascade, retinal transcription factors and retinal structural proteins.1 The list also includes four ubiquitously expressed splicing factors: pre-mRNA processing factor 8 (PRPF8),2 PRPF31,3 PRPF34 and PAP-1, also known as RP9.5 6 Splicing is a complex process that involves the precise excision of introns from pre-mRNA by a macromolecular structure called the spliceosome. Three of the splicing factors implicated in autosomal dominant retinitis pigmentosa (ADRP) are components of the U4/U6-U5 tri-snRNP particle, an essential component of the spliceosome.7 8 Mutations in one of these, PRPF31, have been reported to cause between 5 and 20% of ADRP.9 10 In this report, a new mutation in the PRPF31 gene is described, together with the clinical phenotype. The proband was a 33-year-old female with a corrected visual acuity of 58 and 51 ETDRS letters in the right and left eye, respectively (approximate Snellen equivalents of 6/18 and 6/36). She had a myopic refraction with a spherical equivalence of −2 dioptres in each eye. Nyctalopia had been present since the middle of the second decade, and she had noticed a decrease in her central vision since the beginning of the third decade. At the most recent examination, she had early …