Test Detail
Congenital stationary night blindness (CSNB) - Briard
Ocular · Dog
Congenital visual disease of the Briard described as stationary night blindness, caused by a mutation in the RPE65 gene that alters the visual cycle of the photoreceptors. It mainly affects scotopic vision (night vision), with partial preservation of daytime vision in many cases. Affected dogs show signs from an early age and the disease is not rapidly progressive. Historically it was the key canine model for the development of gene therapy for human Leber congenital amaurosis.
Incidence
Specific to the Briard. After the introduction of genetic testing, carrier frequency has decreased in controlled breeding lines, but no consolidated published figures exist. Limited data for exact frequency.
Breeder management
- Test breeding animals before mating\n- Do not mate two carriers: 25% of the litter would be affected\n- A carrier may be mated to a clear animal; test the offspring intended for breeding\n- Keep carriers in the population by mating them to clear animals to preserve genetic diversity
Specialist notes
Differential diagnosis with other hereditary retinal dystrophies and with progressive PRA. The electroretinogram shows absence of scotopic response with relative preservation of the photopic response. Genetic testing is decisive for screening. Gene therapy is a historic milestone but is not part of routine clinical management.
References
1. Aguirre GD et al. 1998. Congenital stationary night blindness in the dog: common mutation in the RPE65 gene indicates founder effect. Mol Vis 4:23. PMID: 9808841
2. Veske A, Nilsson SE, Narfström K, Gal A. 1999. Retinal dystrophy of Swedish briard/briard-beagle dogs is due to a 4-bp deletion in RPE65. Genomics 57:57-61. PMID: 10191083
3. Acland GM et al. 2001. Gene therapy restores vision in a canine model of childhood blindness. Nat Genet 28:92-95. PMID: 11326284
4. Petersen-Jones SM et al. 2012. Gene augmentation trials using the Rpe65-deficient dog: contributions towards development and refinement of human clinical trials. Adv Exp Med Biol 749:195-211. PMID: 22183331
5. OMIA:001222-9615. Leber congenital amaurosis (retinal dystrophy; CSNB), RPE65-related, perro.
2. Veske A, Nilsson SE, Narfström K, Gal A. 1999. Retinal dystrophy of Swedish briard/briard-beagle dogs is due to a 4-bp deletion in RPE65. Genomics 57:57-61. PMID: 10191083
3. Acland GM et al. 2001. Gene therapy restores vision in a canine model of childhood blindness. Nat Genet 28:92-95. PMID: 11326284
4. Petersen-Jones SM et al. 2012. Gene augmentation trials using the Rpe65-deficient dog: contributions towards development and refinement of human clinical trials. Adv Exp Med Biol 749:195-211. PMID: 22183331
5. OMIA:001222-9615. Leber congenital amaurosis (retinal dystrophy; CSNB), RPE65-related, perro.