Hypomyelination / Shaking Puppy Syndrome (FNIP2-related) - Weimaraner

What does this test assess?

This genetic test analyses the FNIP2 c.880delA variant in the Weimaraner. The condition is known as hypomyelination, central nervous system hypomyelination, Shaking Puppy Syndrome, shaking puppy and SPS. FNIP2 is involved in cellular processes important for normal development and function of nervous tissue.

What does this condition mean?

Hypomyelination means that the myelin sheath around nerve pathways is insufficiently formed. Myelin allows nerve signals to travel quickly and efficiently. When too little myelin is present, young puppies can develop marked muscle tremors and coordination problems. In Weimaraners, tremors are often seen at two to three weeks of age; in many dogs the signs lessen later, although a fine hind-limb tremor can persist.

Inheritance and result

The trait is inherited as an autosomal recessive condition. Dogs with two copies of the tested deletion develop FNIP2-related hypomyelination. Carriers have one copy, are usually clinically healthy, but can pass the variant to offspring.

• Clear: the tested variant was not detected.
• Carrier: one copy of the variant was detected; important for breeding plans.
• Affected: two copies of the variant were detected; this genotype causes hypomyelination for this variant.

Practical value of this test

This test helps breeders avoid carrier-to-carrier matings. It can strongly reduce the risk of puppies with tremors and neurological developmental problems while still allowing valuable carriers to be used responsibly with a suitable mate.

• Identifies carriers that can look healthy.
• Makes planned Weimaraner matings safer.
• Provides clear genetic context for puppies with early tremors.
• Supports transparent communication with buyers and veterinarians.