Interestingly, some cases with apparently autosomal dominant forms were reclassified post-genotyping as X-linked following the identification of mutations in RPGR and RP2. In these instances, female carriers of RPGR-/RP2-associated RP had an almost equally severe phenotype to that of affected males, mimicking a dominant inheritance. The gene discussed is RPGR; the disease is retinitis pigmentosa 1.