Evaluation of the canine RPE65 gene in affected dogs with generalized progressive retinal atrophy.

PURPOSE: The RPE65 gene was screened in 26 breeds of dogs in order to identify potential disease-causing mutations in dogs with generalized progressive retinal atrophy (gPRA).

METHODS

Intronic sequences were obtained from canine genomic DNA by intron-overlapping polymerase chain reactions (PCRs). Mutation analysis was performed by PCR and demonstration of single strand conformation polymorphisms (SSCP). Genomic variations were verified by sequencing.

RESULTS

A series of exonic and intronic single nucleotide polymorphisms (SNPs) were identified in the investigated breeds, but none of the dogs examined showed the typical RPE deletion for retinal dystrophy in Briards nor any other disease-causing mutation.

CONCLUSIONS

The informative SNPs provide evidence allowing indirect exclusion of mutations in the RPE65 gene as causing retinal degeneration in 25 of the 26 dog breeds investigated with presumed autosomal recessively transmitted gPRA.