Sensory neuropathy / SN (FAM134B-related) - Dog

What does this test examine?

This genetic test analyses the FAM134B c.656C>T variant in dogs. The condition is known as sensory neuropathy, SN, hereditary sensory and autonomic neuropathy and HSAN. The result shows whether the dog carries zero, one or two copies of the tested variant.

FAM134B, also known as RETREG1, is important for the survival of sensory neurons. When both gene copies carry the tested variant, nerve cells involved in pain, sensation and position awareness can degenerate severely.

What does this condition mean?

Sensory neuropathy is a serious neurological disorder. Affected dogs can develop progressive ataxia, knuckling or dragging of the paws, loss of sensation, limb hyperextension and self-mutilation of toes or feet. Some dogs can also show urinary incontinence or other autonomic signs.

Early recognition is important because signs may start in young dogs and injuries caused by loss of pain sensation can become severe. This variant is offered as a cross-breed test; clinical context remains important when interpreting the result.

Inheritance and result

The trait is inherited in an autosomal recessive way. A clear dog does not carry the variant. A carrier has one copy and is usually not affected, but can pass the variant to offspring. A dog with two copies has the genotype that causes this form of sensory neuropathy.

• CC - no copy of the tested variant detected.
• CT - carrier: one copy of the tested variant detected.
• TT - affected genotype: two copies of the tested variant detected.

Practical value of this test

This test is valuable because carriers can look healthy. Breeders can identify carriers, plan safe matings and avoid producing puppies with two copies of the variant.

For owners and veterinarians, the result provides clear genetic information when young dogs show neurological signs, paw self-injury or loss of sensation. In breeding programmes, it helps improve health without automatically excluding healthy carriers.