RPGRIP1 and cone-rod dystrophy: Biallelic RPGRIP1 variants have been associated with non-syndromic human IRDs, including retinitis pigmentosa (RP) (Booij et al., 2005), cone-rod dystrophy (CRD) (Hameed et al., 2003), and Leber congenital amaurosis (LCA) type 6 (Dryja et al., 2001).