Oculoskeletal Dysplasia 1 (OSD1) 

 

Gene: COL9A3

Transmission: Autosomal recessive for dwarfism, dominant with variable penetration for eye problems.

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.

For an autosomal dominant genetic disease, an animal must have at least one copy of the mutation in question to be at risk of developing the disease.  Animals with two copies of the mutation generally have more severe symptoms and an earlier onset of the disease than animals with just one copy of the mutation.  One or both of the parents of an animal with the mutation has one or two copies of the mutation.  Animals that have one or two copies of the mutation can pass the mutation on to future generations.

Mutations:

Labrador Retriever mutation: Insertion, COL9A3 gene; c.10 ins.G, p.(A4G fs STOP 46), exon1

Northern Inuit Dog mutation: Substitution, COL9A3 gene; c.700 C>T, p.(R234 STOP)

Medical systems: Skeletal, ocular

Breeds: Labrador Retriever, Samoyed

Age of onset of symptoms: 6 weeks for eye problems

Oculoskeletal Dysplasia 1 is a disease affecting collagen, a protein necessary for normal bone and connective tissue formation.  Clinical signs can first be observed by the age of 4 to 6 weeks and include dwarfism and eyes abnormalities.  Affected dogs have legs that are proportionally shorter than the rest of the body and that gradually curl with the growth of the animal.  Ocular abnormalities can include detachment of the retina and cataracts.  Note that carrier animals will not exhibit short-limbed dwarfism, but they may have more subtle eye changes.

 

References:

OMIA link: [1522-9615]

Sebbag L, Riggs A, Carnevale J. (2020) Oculo-skeletal dysplasia in five Labrador Retrievers. Vet Ophthalmol 23:386-393.  [pubmed/31595625]

Stavinohova R, Hartley C, Burmeister LM, et al. (2019) Clinical, histopathological and genetic characterisation of oculoskeletal dysplasia in the Northern Inuit Dog. PLoS One 14:e0220761.  [pubmed/31415586]

Goldstein O, Guyon R, et al. (2010) COL9A2 and COL9A3 mutations in canine autosomal récessive oculoskeletal dysplasia. Mamm. Genome 27(7-8) :398-408. [pubmed/20686772]