Gene:
phosphodiesterase 6B, cGMP-specific, rod, beta (congenital stationary night blindness 3, autosomal dominant)
Description:
Mice homozygous for the rd mutation display hereditary retinal degeneration which has been considered a model for human retinitis pigmentosa. In affected animals, the retinal rod photoreceptor cells begin degenerating at about postnatal day 8, and by 4 weeks no photoreceptors are left. Farber and Lolley (1974, 1976) showed that degeneration is preceded by accumulation of cyclic GMP in the retina and is correlated with deficient activity of the rod photoreceptor cGMP-phosphodiesterase. Bennett et al. (1996) tested the possibility of altering the course of retinal degeneration through subretinal injection of recombinant replication defective adenovirus that contained the murine cDNA for wildtype beta-PDE. Subretinal injection of rd mice was carried out 4 days after birth, before the onset of rd retinal degeneration. Following therapy, beta-PDE transcripts and enzyme activity were detected, and histologic studies revealed that photoreceptor cell death was significantly retarded.[supplied by OMIM]