Mutations in seven genes (KCNV2, HMCN1, CYP4V2, COL11A1, CAPN5, CACNA1F, and ADAMTS18) typically cause only simple symptoms of RP, while patients with mutations in IFT140 showed RP plus cataract (onset at 7 years of age). Here, IFT140 is linked to retinitis pigmentosa 1.