PRPH2 and retinitis pigmentosa: Retinitis pigmentosa (RP) (OMIM: 268000) is a rare, heterogeneous group of inherited ocular disorders that results in a progressive retinal degeneration.1, 2 The PRPH2 gene (NM_000322.4) (OMIM: 179605), also known as RDS, AOFMD, AVMD, CACD2, DS, MDBS1, PRPH, rd2, RP7 and TSPAN22, is located on chromosome 6p21.1 with three exons spanning 26 395 bp length in human genome (GRCh38/hg38) that encodes a putative protein with 346 amino acids.3 The PRPH2 protein (NP_000313.2) is a member of the transmembrane 4 superfamily, also known as the tetraspanin family.