Stargardt disease 1 / STGD1 (ABCA4-related) - Dog

About Stargardt disease 1

Stargardt disease 1 is an inherited eye disorder in Labrador Retrievers. It is also referred to as STGD1, STGD 1, Stargardt disease, ABCA4-related retinal atrophy, retinal atrophy - generalized and ABCA4-related inherited retinal disease. The condition causes retinal degeneration and leads to gradual loss of vision.

Affected dogs can develop reduced vision in both bright and dim light. Dilated pupils, abnormal light reflexes, reduced retinal reflectivity and vascular attenuation may be observed during eye examination. Progression is usually slow; some dogs retain a degree of vision throughout life.

What does this test detect?

This DNA test detects the ABCA4 variant c.4176dup. This frameshift variant causes loss of ABCA4 function and is associated with Stargardt disease 1 in Labrador Retrievers.

Inheritance and interpretation

Stargardt disease 1 is inherited as an autosomal recessive trait. Dogs with two copies have a genotype consistent with this inherited retinal disorder. Dogs with one copy are carriers; subtle eye findings may occur in older carriers, but obvious visual impairment is mainly expected with two copies.

Practical value of this test

The result helps breeders identify carriers and genetically affected animals and plan breeding combinations more carefully. For veterinarians and owners, the test adds useful context during eye examination and in Labradors with progressive visual signs. A clear result for this variant does not exclude other inherited or acquired causes of retinal degeneration.