W. Kedzierski et al., Deficiency of rds/peripherin causes photoreceptor death in mouse models ofdigenic and dominant retinitis pigmentosa, P NAS US, 98(14), 2001, pp. 7718-7723
Citations number
38
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Retinitis pigmentosa (RP) is a group of inherited blinding diseases caused
by mutations in multiple genes including RDS. RDS encodes rds/peripherin (r
ds), a 36-kDa glycoprotein in the rims of rod and cone outer-segment (OS) d
iscs. Rom1 is related to rds with similar membrane topology and the identic
al distribution in OS. In contrast to RDS, no mutations in ROM1 alone have
been associated with retinal disease. However, an unusual digenic form of R
P has been described. Affected individuals in several families were doubly
heterozygous for a mutation in RDS causing a leucine 185 to proline substit
ution in rds (L185P) and a null mutation in ROM1. Neither mutation alone ca
used clinical abnormalities. Here, we generated transgenic/knockout mice th
at duplicate the amino acid substitutions and predicted levels of rds and r
om1 in patients with RDS-mediated digenic and dominant RP. Photoreceptor de
generation in the mouse model of digenic RP was faster than in the wild-typ
e and monogenic controls by histological, electroretinographic, and biochem
ical analysis. We observed a positive correlation between the rate of photo
receptor loss and the extent of OS disorganization in mice of several genot
ypes. Photoreceptor degeneration in RDS-mediated RP appears to be caused by
a simple deficiency of rds and rom1. The critical threshold for the combin
ed abundance of rds and rom1 is approximate to 60% of wild type, Below this
value, the extent of OS disorganization results in clinically significant
photoreceptor degeneration.