Disease overview

Microphthalmia with coloboma is an inherited canine eye disease characterized by abnormally small eyes and a black spot that extends from the pupil. This disease leads to complete blindness and results when a pregnant mother has a genetic defect that causes vitamin A deficiency in the fetus.

Gene name

RBP4

Inheritance

Autosomal recessive (with maternal genotype effect)

Signs and symptoms

Affected dogs will be born with abnormally small eyes and a black spot that extends from the pupil. Changes in behavior, such as reluctance to go down the stairs or into a dark room, and/or bumping into door frames and furniture, may be signs that a dog is experiencing vision loss.

How is it diagnosed

Thorough examination of the eyes and 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

Kaukonen M, Woods S, Ahonen S, Lemberg S, Hellman M, Hytönen MK, Permi P, Glaser T, Lohi H. Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease. Cell Rep. 2018 May 29;23(9):2643-2652. doi: 10.1016/j.celrep.2018.04.118. PMID: 29847795; PMCID: PMC6546432.

Disclaimer

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