Canine Multifocal Retinopathy 1 (CMR1)

 

Gene: BEST1

Transmission: Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Substitution, BEST1; c.73 C>T, p.(R25 STOP), exon1

Medical system: Eyes

Breeds: Akita, American Bulldog, American Staffordshire Terrier/Amstaff, Anatolian Shepherd Dog, Australian Shepherd, Beagle, Bloodhound, Boerboel, Bordeaux Mastiff, Border Collie, Boston Terrier, Boxer, Brazilian Terrier, Bullmastiff, Cairn Terrier, Cane Corso, Catahoula Leopard Dog, Chihuahua, English Bulldog, French Bulldog, German Shepherd, Golden Retriever, Great Dane, Great Pyrenees, Koolie, Labrador Retriever, Mastiff (Old English), Miniature American Shepherd, Miniature Australian Shepherd, Neapolitan Mastiff, Pomeranian, Poodle - Miniature (Dwarf), Presa Canario, Pug, Rhodesian Ridgeback, Rottweiler, Russell Terrier, Samoyed, Shih Tzu, Terrier Brazileiro, Toy Australian Shepherd, Yorkshire Terrier

Age of onset of symptoms: Between the age of 11 to 16 weeks

Multifocal retinopathy (CMR1) is a condition reported in several breeds of dogs.  Regions of retinal detachment appear in the eyes of affected puppies between the age of 11 and 16 weeks of age. This is accompanied by swellings within the retina that display different sizes and colors when examined by an ophthalmologist.  New lesions stop appearing after 6 to 12 months of age.  Sight is usually not affected.

 

References:

OMIA link: [1444-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Genetics Committee of the American College of Veterinary Opthalmologists (2021) The Blue Book: Ocular disorders presumed to be inherited in purebred dogs. 13th Edition.  [https://ofa.org/wp-content/uploads/2022/10/ACVO-Blue-Book-2021.pdf]

Gornik KR, Pirie CG, Duker JS, Boudrieau RJ. (2014) Canine multifocal retinopathy caused by a BEST1 mutation in a Boerboel. Vet Ophthalmol. 17(5):368-372. [pubmed/23998685]

Hoffmann I, Guziewicz KE, Zanerl B, et al. (2012) Canine multifocal retinopathy in the Australian Shepherd: a case report. Vet Ophthalmol 15(Sup 2):134-138. [pubmed/22432598]

Zangerl B, Wickstrom K, Slavik J, Lindauer SJ, et al. (2010) Assessment of canine BEST1 variations identifies new mutations and establishes an independent bestrophinopathy model (cmr3). Molecular Vision 16:2791-2804. [pubmed/21197113]

Guziewica KE, Zangerll B, Lindauer SJ, et al. (2007) Bestrophin gene mutations cause canine multifocal retinopathy: A novel animal model for Best disease. Investigative Ophthalmology and Visual Science 48(5):1959-1967. [pubmed/1746024]