“…The latter situation is the case for the four RP genes that encode mRNA splicing factors, namely RP9 (PAP1), RP11 (PRPF31), RP13 (PRPC8), and RP18 (HPRP3) (MIM]s 607331,606419,607300,and 607301,respectively). Dominant mutations in these four ubiquitously expressed genes cause forms of RP (MIM]s 180104, 600138, 600059, and 601414, respectively) [Vithana et al, 2001;McKie et al, 2001;Chakarova et al, 2002;Keen et al, 2002]. They all encode components of the spliceosome, a macromolecular complex composed of proteins and RNA molecules whose major function is to splice introns out of RNA transcripts [Zhou et al, 2002;Maita et al, 2004Maita et al, , 2005.…”