Several key genes are frequently mutated in RP, including RHO (rhodopsin), responsible for about 25% of adRP cases; USH2A, associated with 20% of arRP cases; and RPGR (retinitis pigmentosa GTPase regulator), which accounts for over 80% of XL-RP cases. The gene discussed is RPGR; the disease is retinitis pigmentosa 1.