Breeds Affected: Beagle
Samples Accepted: Blood, Buccal Swabs
Disease Information: Symptoms in the beagle are usually first noted around 3 weeks of age, when pups begin to walk. Affected pups have a broad-based stance, trouble moving deliberately, loss of balance, and tremors.
Inheritance Information: Cerebellar Abiotrophy is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/ca The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/ca carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
ca/ca The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/ca carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/ca x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/ca x N/ca) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (ca/ca) should not be used for breeding.
Test Information: This mutation test identifies an 8 base deletion in exon 29 of the SPTBN2 gene.
Forman, O.P., De Risio, L., Stewart, J., Mellersh, C.S., Beltran, E.: Genome-wide mRNA sequencing of a single canine cerebellar cortical degeneration case leads to the identification of a disease associated SPTBN2 mutation. BMC Genet 13:55, 2012. Pubmed reference: 22781464. Doi: 10.1186/1471-2156-13-55.
Further information is available at the Online Mendelian Inheritance in Animals website.