OCULAR FINDINGS ASSOCIATED WITH A 3-BASE-PAIR DELETION IN THE PERIPHERIN-RDS GENE IN AUTOSOMAL-DOMINANT RETINITIS-PIGMENTOSA

Affected members of a family with autosomal dominant retinitis pigment osa were found to have a 3 base pair deletion at codon 118 or 119 of t he retinal degeneration slow gene. This mutation causes the loss of a highly conserved cysteine residue in the predicted third transmembrane domain of peripherin-rds, a photoreceptor specific structural glycopr otein localised to both rod and cone outer segment disc membranes. Fou r of these individuals underwent detailed clinical, psychophysical, an d electroretinographic testing in order to characterise their photorec eptor dysfunction. Nyctalopia was reported early in the second decade by all patients. Global rod and cone dysfunction was recorded by the t hird decade with severe reduction of both photopic and scotopic functi on by age 30 years. This retinal degeneration slow gene mutation may l ead to the primary loss of both rod and cone photoreceptor function.