X-linked tremor / Shaking Puppy Syndrome (PLP1-related) - English Springer Spaniel

What does this test assess?

This genetic test analyses the PLP1 c.110A>C variant in the English Springer Spaniel. The condition is known as X-linked tremor, Shaking Puppy Syndrome, shaking pup, SPS, SHP and PLP1-related hypomyelination. PLP1 encodes proteolipid protein 1, an important myelin protein in the central nervous system.

What does this condition mean?

In affected puppies, myelin around nerve pathways is not formed properly. As a result, signals in the brain and spinal cord are transmitted less efficiently. Clinically this can cause marked tremors, difficulty standing, moving and eating, ataxia, reduced growth, seizures and a very poor prognosis in affected males.

Inheritance and result

The trait is inherited in an X-linked recessive pattern. Males have one X chromosome; a male carrying the variant is therefore affected. Females with one copy are carriers and can pass the variant to offspring. Because of X-inactivation, some carrier females may show mild or temporary tremors, but the main breeding impact is the risk of affected male puppies.

• Clear: the tested variant was not detected.
• Carrier: one copy of the variant was detected; this is mainly relevant in females and for breeding plans.
• Affected: the genotype causes PLP1-related X-linked tremor for this variant, especially in hemizygous males.

Practical value of this test

This test is valuable because carriers may be clinically subtle while the variant can still produce severely affected puppies within a line. Testing breeding dogs in advance helps breeders plan matings, identify carrier females correctly and strongly reduce the risk of Shaking Puppy Syndrome in English Springer Spaniels.

• Helps identify carrier females before breeding.
• Prevents an X-linked risk from remaining hidden in a breeding line.
• Provides clear genetic context for puppies with tremors or coordination problems.
• Supports transparent communication with buyers, veterinarians and breed clubs.