Macular corneal dystrophy / MCD (CHST6-related) - Dog

What does this test analyse?

This genetic test analyses the CHST6/LOC489707 c.814C>A-variant in dogs. The condition is known as macular corneal dystrophy, macular dystrophy of the cornea or MCD. It is especially relevant for breeds and lines in which this variant has been described, including Labrador Retriever and Australian Labradoodle.

What does this condition mean?

MCD affects the cornea. The cornea can gradually become cloudy and develop multiple off-white to yellow-brown opacities. Vision can therefore decline, especially as the corneal haze progresses. Because visible signs often appear later in life, a breeding dog may have passed on the variant before clinical signs are obvious.

Inheritance and result

The trait is inherited as an autosomal recessive condition. A dog with one copy is a carrier and can pass the variant on without being affected. A dog with two copies has the genetic result that causes the tested form of MCD. The result therefore separates clear, carrier and affected genetic status.

Practical value of this test

This test has practical value for breeders, owners and veterinarians who want to manage inherited eye disease in a line more precisely. It helps identify hidden carriers, avoid risk matings and interpret eye screening with stronger genetic context.

• Supports breeding selection by identifying carriers before two carriers are paired.
• Helps reduce the risk of puppies inheriting two copies of the variant.
• Adds useful context for dogs with corneal clouding, punctate opacities or reduced vision.
• Makes communication with puppy buyers and breed clubs clearer because the tested variant is named explicitly.

Result in brief

• Clear (C/C): the tested variant was not detected.
• Carrier (C/A): one copy was detected; the dog can pass the variant on.
• Affected genetic result (A/A): two copies were detected; this genotype causes the tested form of MCD.