Progressive retinal atrophy / gPRA (CCDC66-related) - Schapendoes

What does this test examine?

This genetic test analyses the CCDC66 variant c.521_522insA in the Schapendoes. The condition is known as generalized PRA / gPRA / gPRA-SPD / EOPRA / PRA-CCDC66. The result shows whether the dog carries zero, one or two copies of the tested variant.

Progressive retinal atrophy (PRA) is a group of inherited retinal diseases in which photoreceptor cells gradually lose function. In this test, the relevant cause is in the CCDC66 gene, allowing a specific breed-related PRA risk to be identified.

What does this condition mean?

In Schapendoes dogs with gPRA, young animals often appear normal. The disease usually develops at about 2 to 5 years of age, starts with night blindness and difficulty adapting to dim light, and can later affect day vision.

Early signs can be subtle: reduced vision in dim light, hesitancy in unfamiliar spaces, difficulty avoiding obstacles and later loss of day vision. DNA testing identifies the inherited status before visible signs appear or before a breeding combination is chosen.

Inheritance and result

The trait is autosomal recessive. The result gives a lifelong genetic status for the tested variant.

• N/N - no copy of the tested variant detected.
• N/insA - one copy of the tested variant detected.
• insA/insA - two copies of the tested variant detected.

Practical value of this test

This test is especially useful for identifying clinically healthy carriers before breeding. It helps breeders preserve Schapendoes lines while avoiding combinations that can produce puppies with gPRA.

• Helps breeders include inherited eye health in selection and mating plans.
• Identifies hidden carriers or genetically positive dogs before they are used for breeding.
• Reduces the risk of puppies with a predictable inherited PRA predisposition.
• Gives owners and breeders clear information for family screening, line management and eye-health follow-up.
• Supports transparent communication when selling, buying or selecting breeding animals.