The large size of both genes explains at least in part the high prevalence of RP secondary to variants in these genes,12 but presumed founder mutations such as EYS c.4957dupA (p.S1653fs) in Japanese13 and EYS c.6416G > A (p.C2139Y)4 and USH2A c.2802 T > G (p.C934W)14 in ethnic Chinese also influences the prevalence of RP caused by EYS and USH2A variants. The gene discussed is USH2A; the disease is retinitis pigmentosa 1.