A novel splicing mutation in the PRPH2 gene causes autosomal dominant retinitis pigmentosa in a Chinese pedigree

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 ({"type":"entrez-nucleotide","attrs":{"text":"NM_000322.4","term_id":"194248075","term_text":"NM_000322.4"}}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 ({"type":"entrez-protein","attrs":{"text":"NP_000313.2","term_id":"118572596","term_text":"NP_000313.2"}}NP_000313.2) is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. The majority of the members are cell‐surface proteins which were identified by the presence of four hydrophobic domains. The PRPH2 protein is a membrane‐associated glycoprotein, which is restricted to the area of photoreceptor outer segment discs.4 PRPH2 functions as an adhesion molecule by stabilization and compaction of outer segment discs. PRPH2 and ROM1 (OMIM: 180721) can be assembled into noncovalent tetramers (heterodimer) in vivo using disulphide bonds and higher order disulphide‐linked oligomers, thereby involving in photoreceptor disc morphogenesis.5 Mutations in the PRPH2 gene are involved with assorted blinding diseases of the retina, inducing degenerations in both central retinal and peripheral retinal.6, 7, 8 The relationships between the mutations in the PRPH2 gene and the resultant diseases in the patients are variable; making genotype/phenotype correlations different. PRPH2 mutation in RP patients and genotype/phenotype relationship have not been well described in the Chinese population.