RP2 and retinitis pigmentosa 1: We excluded that additional nucleotide variations in RP2 and RPGR may explain the phenotype of RP in patients with ORF15 mutations and performed mutation screenings in exons 1 through 15, 9a, 15a, and 15b of RPGR and all coding exons of RP2. In addition to pathogenic mutations, we identified several polymorphic sequence alterations (Table 2 and Table 3).