EYS and retinitis pigmentosa 1: We conducted stepwise genetic screening for Japanese patients with RP using direct Sanger sequencing for the two EYS founder mutations in Japan, targeted NGS of all coding regions of EYS, WGS, and additional Sanger sequencing for the Alu element insertion in RP1, and determined genetic diagnoses in 98 (44.5%) of 220 analyzed patients.