Congenital stationary night blindness / Leber congenital amaurosis (RPE65-related) - Briard

What does this test examine?

This genetic test analyses the RPE65 variant c.460_463del in the Briard. The disorder is commonly referred to as Congenital Stationary Night Blindness, CSNB, Leber congenital amaurosis, LCA, RPE65-related retinal dystrophy and retinal pigment epithelial dystrophy.

What does RPE65-related CSNB / LCA mean?

RPE65 is essential for the visual cycle in the retinal pigment epithelium. When this process is disrupted, photoreceptors process light signals less efficiently. Affected Briards have reduced vision in low light and may need bright light to function better. The condition can also gradually lead to additional retinal degeneration.

This analysis is practically important because the names partly overlap: CSNB highlights night blindness, LCA highlights the congenital severe retinal disorder, and retinal pigment epithelial dystrophy describes the tissue layer involved. For the customer, the key question is the same: does the dog carry the RPE65 deletion that causes this Briard eye disorder?

Inheritance and result

The RPE65 variant is inherited as an autosomal recessive trait. Carriers with one copy do not develop the disorder from one copy, but can pass the variant on. Dogs with two copies develop RPE65-related retinal dystrophy / CSNB. Testing breeding dogs helps prevent accidental carrier x carrier matings.

Practical value of this test

• Helps Briard breeders identify carriers and plan combinations in which affected puppies are not expected.
• Supports genetic diversity because carriers can be used responsibly with clear-tested partners.
• Provides clear context for puppies or adult dogs with night blindness, reduced low-light vision or retinal findings.
• Makes communication about CSNB, LCA and RPE65-retinal dystrophy unambiguous for breeder, owner and veterinarian.
• Is valuable in lines with eye problems, related carriers or RPE65 test results.