Mutation screening of the peropsin gene, a retinal pigment epithelium specific rhodopsin homolog, in patients with retinitis pigmentosa and allied diseases.
OBJECTIVE
To investigate the peropsin gene (RRH), encoding a retinal pigment epithelium homolog of the rod-expressed opsin (rhodopsin), for the presence of pathogenic mutations causing retinitis pigmentosa (RP) or other retinal degenerations.


METHODS
All seven exons composing the RRH open reading frame and the immediate intron sequences were analyzed by direct nucleotide sequencing of 613 patients with forms of retinal degeneration.


RESULTS
One patient with retinitis punctata albescens was a heterozygote with the missense change Cys98Tyr (TGT>TAT, c.293G>A). This change affects the homologous residue that is the target of the rhodopsin mutation Cys110Tyr, a reported cause of dominant RP. Unfortunately, none of the patient's relatives were available for a segregation analysis to determine if this change is unambiguously associated with disease. No definite pathogenic mutation was found in any of the other 612 patients who were evaluated.


CONCLUSIONS
The Cys98Tyr is a possible cause of retinitis punctata albescens, although this conclusion is tentative because the change was found in only one patient. Our results indicate that the peropsin gene is not a common cause of RP or some related retinal degenerations, at least in the set of patients we analyzed.
Rivolta
Carlo
C
Harvard Medical School, Massachusetts Eye and Ear Infirmary, Ocular Molecular Genetics Institute and The Berman-Gund Laboratory for the Study of Retinal Degenerations, Boston, MA, USA. carlo.rivolta@unil.ch
Berson
Eliot L
EL
Dryja
Thaddeus P
TP
D003545:Cysteine; D004252:DNA Mutational Analysis; D006579:Heterozygote; D006801:Humans; D020125:Mutation, Missense; D012162:Retinal Degeneration / Q000235:genetics*; D012174:Retinitis Pigmentosa / Q000235:genetics*; D012243:Rhodopsin / Q000235:genetics*; D014443:Tyrosine
C504671:RRH protein, human; D014443:Tyrosine; D012243:Rhodopsin; D003545:Cysteine