Progressive retinal atrophy / Dominant PRA (RHO-related) - Bullmastiff / English Mastiff

What does this test examine?

This genetic test analyses the RHO variant c.11C>G in the Bullmastiff / English Mastiff. The condition is known as progressive retinal atrophy / D-PRA / Dominant PRA / ADPRA. 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 RHO gene, allowing a specific breed-related PRA risk to be identified.

What does this condition mean?

In this dominant PRA form, dogs may initially appear normal, after which vision gradually deteriorates. Night vision and recovery after bright light can be impaired, and genetically positive dogs may develop clear vision loss in adulthood. Two copies can be more severe than one copy.

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 dominant. The result gives a lifelong genetic status for the tested variant.

• C/C - no copy of the tested variant detected.
• C/G - one copy of the tested variant detected.
• G/G - two copies of the tested variant detected.

Practical value of this test

Because this PRA form is dominant, one copy is enough to identify the tested inherited risk. This makes the result especially practical for breeders: genetically positive dogs can be recognised early, even before obvious eye signs are present.

• 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.