PRPH2 and retinitis pigmentosa 1: Interestingly, Shankar et al. reported that PRPH2 trans modifiers can influence the phenotype in PRPH2 retinopathy as they found that patients with the Gln304-Lys310-Asp338 (which is usually classified as a polymorphism) haplotype in trans with the PRPH2 mutation were more likely to have severe phenotypes (CRD, RP, CACD) rather than PD [9].