Canine multiple system degeneration / CMSD (SERAC1-related) - Chinese Crested

What does this test examine?

This genetic test analyses the SERAC1 c.182+1_182+4del variant in the Chinese Crested. The disorder is called canine multiple system degeneration, abbreviated CMSD, and is also described as striatonigral and cerebello-olivary degeneration or hereditary cerebellar neuronal abiotrophy.

What does this mean for the dog?

CMSD is a severe progressive neurological disorder in which several parts of the central nervous system are affected. The cerebellum, brainstem, caudate nucleus and substantia nigra are important for movement, posture and coordination. Affected puppies can develop intention tremors, ataxia, hypermetria, poor balance, frequent falling, abnormal posture and eventually loss of voluntary movement.

Practical value of this test

• The result distinguishes clear dogs, carriers and dogs with two copies of the tested variant.
• Breeders can identify carriers deliberately and avoid pairings that may produce affected puppies.
• The test helps distinguish CMSD from other forms of cerebellar ataxia or movement disorder within the breed.

The condition is inherited as an autosomal recessive trait. One copy means carrier status; two copies cause the CMSD genotype. This variant disrupts normal SERAC1 splicing and is tested specifically in this breed.