The role of the peripherin/RDS gene in retinal dystrophies

Peripherin/RDS is a transmembrane glycoprotein expressed in vertebrate phot oreceptors. It is located at the rim of the disc membranes of the photorece ptor outer segments, where it is thought to play an important role in foldi ng and stacking of the discs. Initially, the identification of a mutation i n the rds mouse model defined the role of this gene in hereditary retinal d ystrophies. To date over 60 different mutations have been reported in human retinal diseases, with most being restricted to single families. A charact eristic of mutations in the peripherin/RDS gene is the broad phenotypic spe ctrum in patients, and the variability in clinical expression, even within families. Thus, genotype-phenotype correlations are difficult and only reli able for a minority of mutations.