Disease overview

Stargardt disease (STGD) is an eye disorder characterized by late-onset retinal degeneration that causes visual impairment and even total blindness. This condition causes a progressive degeneration of the rod and cone photoreceptor cells in the retina that are responsible for sensing light. Rod cells are responsible for vision in low light conditions and for detecting and following movement, while cone cells detect color and adjust brightness, but do not work as well in low light. Both daytime and dim light vision are impaired. Vision tends to decline with age, though some dogs may not experience a complete loss of vision in their lifetime.

Gene name

ABCA4

Inheritance

Autosomal recessive

Signs and symptoms

Symptoms include blurred vision and difficulty adapting between bright and dim light environments. Clinical signs include dilated pupils and decreased response to light, which are particularly evident in older dogs.

How is it diagnosed

Thorough examination of the eyes and clinical signs, including diffuse retinal degeneration and reduction of the number of photoreceptors (with more profound abnormality in cone cell function as compared to rod cell function). Genetic testing for mutations in the ABCA4 gene assists veterinarians with diagnosis and helps breeders identify affected and carrier dogs.

Breeds at higher risk

Citations

Mäkeläinen S, Gòdia M, Hellsand M, Viluma A, Hahn D, Makdoumi K, Zeiss CJ, Mellersh C, Ricketts SL, Narfström K, Hallböök F, Ekesten B, Andersson G, Bergström TF. An ABCA4 loss-of-function mutation causes a canine form of Stargardt disease. PLoS Genet. 2019 Mar 19;15(3):e1007873. doi: 10.1371/journal.pgen.1007873. PMID: 30889179; PMCID: PMC6424408.

Ekesten B, Mäkeläinen S, Ellis S, Kjellström U, Bergström TF. Abnormal Appearance of the Area Centralis in Labrador Retrievers With an ABCA4 Loss-of-function Mutation. Transl Vis Sci Technol. 2022 Feb 1;11(2):36. doi: 10.1167/tvst.11.2.36. PMID: 35201338; PMCID: PMC8883171.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.