Breeds Affected: Chinese Crested Dog
Samples Accepted: Blood, Buccal Swabs
Disease Information: Canine Multiple System Degeneration (CMSD) is also known as Progressive Neuronal Abiotrophy (PNA). It is a progressive neurological disorder in which normal-appearing pups start to show tremor and problems with balance between the ages of 3-6 months. As the disease progresses, gait abnormalities and balance problems are associated with frequent falling, abnormal body posture and erratic eye movements. Disease progression or complications lead to death or humane euthanasia by 18-24 months of age.
Inheritance Information: CMSD 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/cmsd The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/cmsd carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
cmsd/cmsd The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/cmsd carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/cmsd 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/cmsd x N/cmsd) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (cmsd/cmsd) should not be used for breeding.
Test Information: This test identifies a four base deletion in exon 15 of the SERAC1 gene.
Zeng, R. 2013. Doctoral Dissertation, University of Missouri: Molecular genetic studies in canine inherited diseases including neonatal cerebellar ataxia, degenerative myelopathy and multiple system degeneration, Chapter 5: Canine Multiple System Degeneration: Next Generation Whole Genome Sequencing Revealed Two SERAC1 Mutations Causing Canine Multiple System Degeneration.
Further information is available at the Online Mendelian Inheritance in Animals website.