Of the 12 patients from nine families with PRPH2-associated RP, including eight families with the autosomal dominant trait and one family with the autosomal recessive trait, 6/12 reported experiencing decreased vision or visual field defects in the third to sixth decade of life, and 4/12 reported experiencing night blindness or poor vision since childhood. This evidence concerns the gene PRPH2 and retinitis pigmentosa 1.