RS1 and Leber congenital amaurosis: There are multiple gene therapy clinical trials underway or planned for other IRD conditions [19,32,33,34,35,36,37,38,39,40] including choroideraemia (CHM, OMIM*300390), achromatopsia (CNGA3, OMIM*60053; CNGB3, OMIM*605080), non-syndromic RP (RPGR, OMIM*312610; MERTK, OMIM*604705), X-linked retinoschisis (RS1, OMIM*300839), Leber congenital amaurosis (LCA, CEP290, OMIM*610142) and Usher syndrome (MYO7A, OMIM*276903).