Hereditary cataract / HC HSF4-2 (HSF4-related) - Dog

What does this test examine?

This genetic test analyses the HSF4 c.971_972insC variant in Boston Terrier, French Bulldog and Staffordshire Bull Terrier. The disorder is known as hereditary cataract, primary hereditary cataract, HC, PHC and inherited cataract. Cataract means that the normally clear lens becomes opaque, reducing the amount of light reaching the retina and impairing vision.

What does it mean for the dog?

HSF4 encodes a heat-shock transcription factor important for lens development and lens cells. When this variant is present, the lens can become cloudy at a young or adult age. Depending on breed, genotype and penetrance, cataracts can differ in age of onset, severity and progression. Affected dogs may see less clearly, move less confidently, show visible eye changes and become blind in severe cases.

Practical value of this test

• Breeders can identify carriers before mating, even when the dog itself has no cataract.
• The test helps avoid carrier-to-carrier matings, preventing puppies with two copies of this HSF4 variant.
• For Boston Terriers, French Bulldogs and Staffordshire Bull Terriers, the result gives concrete information for selection against hereditary cataract.
• In young dogs from risk lines, the result can help explain early lens changes genetically.

The condition is inherited as an autosomal recessive trait. One copy makes a dog a carrier; two copies cause the tested form of HSF4-related hereditary cataract.