Disease overview

Bardet-Biedl syndrome 4 is a form of progressive retinal atrophy (PRA). It is a non-painful disease that affects both types of photoreceptors: rods and cones. Rods are essential for night vision and movement, while cones are used for day vision and color.

Gene name

BBS4

Inheritance

Autosomal recessive

Signs and symptoms

Progressive retinal atrophy (PRA) is characterized by slow, progressive vision loss in both eyes. This provides more opportunities for helping an affected dog adapt to its changing visual environment. A dog with PRA can exhibit symptoms of vision loss that include a reluctance to go down stairs or into a dark room, and/or bumping into door frames and furniture. There may be a more noticeable reflectivity in their eyes.

How is it diagnosed

A veterinarian will conduct a thorough exam that includes the eyes, as well as review health history and any clinical signs. A veterinary ophthalmologic exam can determine if there are changes in the eye that have or will lead to vision loss. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.

Breeds at higher risk

Citations

Chew T, Haase B, Bathgate R, Willet CE, Kaukonen MK, Mascord LJ, Lohi HT, Wade CM. A Coding Variant in the Gene Bardet-Biedl Syndrome 4 (BBS4) Is Associated with a Novel Form of Canine Progressive Retinal Atrophy. G3 (Bethesda). 2017 Jul 5;7(7):2327-2335. doi: 10.1534/g3.117.043109. PMID: 28533336; PMCID: PMC5499139.

Chew T, Haase B, Willet CE, Wade CM. Exclusion of known progressive retinal atrophy genes for blindness in the Hungarian Puli. Anim Genet. 2017 Aug;48(4):500-501. doi: 10.1111/age.12553. Epub 2017 Apr 5. PMID: 28378943.

Disclaimer

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