Unlike the expected pattern of an X-linked disease affecting only males, recent studies have reported that RP2 and RPGR mutation cause variable RP phenotypes in heterozygous female patients.[30–32] Furthermore, it is reported that mutations in RP2 and RPGR account for 8.5 % of patients with RP in provisional autosomal dominant families [33]. This evidence concerns the gene RP2 and retinitis pigmentosa 1.