Canine Multifocal Retinopathy (CMR1)

Related Terms: BEST1, Bestrophin 1, Canine Multifocal Retinopathy 1, Multifocal Retinopathy 1

Type: DNA

Sample Types: Cheek brushes/swabs or Fresh EDTA blood

Changes in the retina of the eye are present by 4 months of age

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Sample Processing

Cost: $55.00

Species and Breeds
Canine - Australian Shepherd
Canine - Bulldog (English)
Canine - Bullmastiff
Canine - Dogue de Bordeaux
Canine - French Bulldog
Canine - Great Pyrenees
Canine - Mastiff, English

Order Test We do not provide kits. Please collect the sample following the sample collection and shipping instructions before ordering a test.

Vision loss characterized by bumping into things, not being able to catch objects, and increasingly hypermetric gait of the front legs (i.e. trying to feel the way rather than see).


Autosomal recessive

Multifocal retinopathy usually manifests in young dogs between 3–4 months of age as multifocal bullous retinal detachments that tend to progress slowly to form larger subretinal lesions, and consequently, retinal degeneration and atrophy in older dogs.

BEST1 and NM_001097545.1:c.73C>T

Explanation of Results
Genotype Phenotype Interpretation
2-2 (Homozygous Disease Variant) Unhealthy (Affected) Homozygous Affecteds (2-2) are expected to develop signs consistent with Canine Multifocal Retinopathy (CMR1) and all of their offspring will inherit a disease variant allele. Parents, offspring and relatives should also be tested. You may choose to contact us for a consultation on the management of this disease. 1 = Normal allele; 2 = Variant allele.
1-2 (Heterozygous) Healthy (Carrier) Heterozygous Carriers (1-2) are not expected to develop signs of Canine Multifocal Retinopathy (CMR1) but each of their offspring has a chance of inheriting a disease variant allele. Parents, offspring and relatives should also be tested. 1 = Normal allele; 2 = Variant allele.
1-1 (Homozygous Normal) Healthy (Normal, Clear) Homozygous Normals (1-1) are not expected to develop signs of Canine Multifocal Retinopathy (CMR1) and none of their offspring will inherit the disease variant allele. 1 = Normal allele; 2 = Variant allele.

Donner J, Kaukonen M, Anderson H, Möller F, Kyöstilä K, Sankari S, Hytönen M, Giger U, Lohi H. Genetic Panel Screening of Nearly 100 Mutations Reveals New Insights into the Breed Distribution of Risk Variants for Canine Hereditary Disorders. PLoS One. 2016 Aug 15;11(8):e0161005. doi: 10.1371/journal.pone.0161005. PMID: 27525650; PMCID: PMC4985128. Gornik KR, Pirie CG, Duker JS, Boudrieau RJ. Canine multifocal retinopathy caused by a BEST1 mutation in a Boerboel. Vet Ophthalmol. 2014 Sep;17(5):368-72. doi: 10.1111/vop.12095. Epub 2013 Sep 3. PMID: 23998685. Hoffmann I, Guziewicz KE, Zangerl B, Aguirre GD, Mardin CY. Canine multifocal retinopathy in the Australian Shepherd: a case report. Vet Ophthalmol. 2012 Sep;15 Suppl 2(0 2):134-8. doi: 10.1111/j.1463-5224.2012.01005.x. Epub 2012 Mar 20. PMID: 22432598; PMCID: PMC3787078. Guziewicz KE, Slavik J, Lindauer SJ, Aguirre GD, Zangerl B. Molecular consequences of BEST1 gene mutations in canine multifocal retinopathy predict functional implications for human bestrophinopathies. Invest Ophthalmol Vis Sci. 2011 Jun 23;52(7):4497-505. doi: 10.1167/iovs.10-6385. PMID: 21498618; PMCID: PMC3175949. Guziewicz KE, Zangerl B, Lindauer SJ, Mullins RF, Sandmeyer LS, Grahn BH, Stone EM, Acland GM, Aguirre GD. Bestrophin gene mutations cause canine multifocal retinopathy: a novel animal model for best disease. Invest Ophthalmol Vis Sci. 2007 May;48(5):1959-67. doi: 10.1167/iovs.06-1374. PMID: 17460247; PMCID: PMC1931491.