As RP1 mutations cause CRD, RP, or macular dystrophy in either autosomal recessive or dominant states depending on the mutation location and type26, careful evaluations of the family history and the locations of variants in RP1 are important, particularly when a single heterozygous disease-causing RP1 variant is found and the family history does not indicate autosomal dominant inheritance. The gene discussed is RP1; the disease is retinitis pigmentosa 1.