Canine Multifocal Retinopathy 1 (CMR1)

Quick Summary

Canine multifocal retinopathy 1 is an inherited eye disease characterized by areas of retinal detachment. The disease does not typically lead to blindness or vision deficits.
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CMR1
retinopathy

Phenotype: Affected dogs typically present with multiple, discrete circular areas of retinal detachment between 11 and 16 weeks of age. Fluid accumulates under the detached retina resulting in gray, tan, orange or pink “blisters” in the eye. Progression of retinal changes is slow, ceases by 1 year, and does not lead to blindness.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal, CMR1 = Canine multifocal retinopathy 1

Breeds appropriate for testing: American Bulldog, American Bully, Aussiedoodle, Australian Koolie, Australian Shepherd, Brazilian Terrier, Bulldog, Bullmastiff, Cane Corso, Dogue de Bordeaux, English Bulldog, French Bulldog, Great Pyrenees, Havanese, Koolie, Mastiff, Miniature American Shepherd, Miniature Australian Shepherd, Olde English Bulldogge, Perro de Presa Canario, Shorty Bull, South African Boerboel, Toy Australian Shepherd

Explanation of Results:

  • Dogs with N/N genotype will not have canine multifocal retinopathy 1 and cannot transmit this CMR1 variant to their offspring.
  • Dogs with N/CMR1 genotype will not have canine multifocal retinopathy 1, but are carriers. They will transmit this CMR1 variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% canine multifocal retinopathy 1-affected puppies.
  • Dogs with CMR1/CMR1 genotype will develop canine multifocal retinopathy 1, an eye disease, and will transmit this variant to all of their offspring.

Results of this test can be submitted to the OFA (Orthopedic Foundation for Animals)

Price

$50 one test per animal
$30 as additional test (same animal)
Additional $5 discount on 3 or more dogs

Panels Available
Additional Details

Canine multifocal retinopathy 1 (CMR1) is an inherited eye disease caused by a mutation (c.73C>T) in the Bestrophin 1 gene that results in a shortened, dysfunctional protein. Affected dogs typically present with multiple, discrete circular areas of retinal detachment between 11 and 16 weeks of age. Fluid accumulates under the detached retina resulting in gray, tan, orange or pink “blisters” in the eye. Progression of retinal changes is slow, ceases by 1 year, and does not lead to blindness. In some cases, the blisters appear to heal as the dog ages but vision loss has been reported.

The disease is inherited in an autosomal recessive fashion thus two copies of the CMR1 mutation must be present to produce the disease. Breeding two carriers is predicted to produce 25% affected pups.

The VGL offers genetic tests for CMR1, CMR2, and CMR3 mutations. Genetic screening helps breeders establish the genetic status of breeding stock and select mating pairs appropriately in order to reduce the risk of producing affected offspring.

 

Note: CMR1, CMR2, and CMR3 mutations have different breed origins and distributions and thus test selection needs to be breed-appropriate. See "Breeds appropriate for testing" list on each page.
Turnaround Time
5-10 business days

Species

Dog

Type of Test

Results Reported As
Test Result Canine Multifocal Retinopathy 1

N/N

Normal. No copies of the CMR1 mutation.

N/CMR1

Carrier. 1 copy of the CMR1 mutation. Dog is normal.

CMR1/CMR1

Affected. 2 copies of the CMR1 mutation. Dog will develop multifocal retinopathy.

References

Gornik, K.R., Pirie, C.G., Duker, J.S., & Boudrieau, R.J. (2014). Canine multifocal retinopathy caused by a BEST1 mutation in a Boerboel. Veterinary Ophthalmology, 17(5), 368-372. doi: 10.1111/vop.12095

Donner, J., Kaukonen, M., Anderson, H., Moller, F., Kyostila, K., Sankari, S., Hytonen, M., Giger, U., & Lohi, H. (2016). Genetic Panel Screening of Nearly 100 Mutations Reveals New Insights into the Breed Distribution of Risk Variants for Canine Hereditary Disorders. PLoS One, 11(8). doi: 10.1371/journal.pone.0161005