EYS and retinitis pigmentosa 1: For example, a Japanese population study of 68 patients found that one-third of patients with non-syndromic autosomal recessive RP carried pathogenic gene variants in the EYS gene [4], while a similar study from a western European ancestry cohort approximated that the prevalence of EYS variants accounted for only 5% of autosomal recessive RP in a cohort of 245 patients [5].