Kuehlewein L, Zobor D, Andreasson SO, et al. - Researchers conducted this prospective, longitudinal, observational cohort study to evaluate clinical characteristics, genetic findings, and genotype-phenotype correlations in patients with retinitis pigmentosa (RP) associated with biallelic sequence variations in the PDE6A gene in preparation for a gene supplementation trial. Patients with retinitis pigmentosa, sequence variants in PDE6A, and the ability to provide informed consent were recruited. Fifty-seven patients from 44 families were involved (32 female patients [56%]; mean [SD], 40 [14] years). It appeared that 17 of the PDE6A variants found in these patients were novel. In terms of clinical results, the condition between the right and left eyes was strongly symmetrical and visual impairment in 90% of patients was mild to moderate, offering a window of opportunity for gene therapy.