Interestingly, one report suggested that unique point mutations in specific rhodopsin codons might lead to distinct RP phenotypes [17]: in one family with a p.Asp190Tyr mutation, the phenotype was one of severe and diffuse typical RP, while in another family with a p.Asp190Asn mutation, the phenotype was one typical of sector RP with an inferior regional predilection. This evidence concerns the gene RHO and retinitis pigmentosa 1.