Affected gene: COL9A3
 
Inheritance: Autosomal recessive
 
Mutation: CanFam3.1 chr24 g.46653422_46653423insG
 
OMIA link: 001522-9615
 
Breeds appropriate for testing: Labrador Retriever
 

 
Symptoms
The first clinical signs are visible as early as 4 to 6 weeks of age. Visual abnormalities include cataracts, vitreous syneresis, and retinal detachment. Retinal dysplasia, retinal degeneration, or a lens coloboma may also occur. The clinical expression of the disease ranges from asymptomatic cases to complete loss of vision.
 
At the skeletal level, limb dwarfism, shortening of the ulna, radial bowing, osteoarthritis, and hip and elbow dysplasia are commonly observed in affected dogs.