Sensory Neuropathy Border Collie Type (SN)
Sensory neuropathy Border Collie type is an inherited progressive neurological disorder which affects the Border Collie breed. Generally, neuropathy is a disease of the peripheral nerves. The peripheral nervous system is responsible for sensation feeling to the skin and the muscle control. Disease of the sensory nerves causes the sensory neuropathy. Sensory neuropathy can be divided into two groups, inherited or acquired through disease processes or trauma. Inherited sensory neuropathy is a rare disorder but has been reported in several countries worldwide. Except in Border collies, the disorder has been diagnosed also in Brittany spaniel, Welsh corgi and a Siberian husky. Inherited forms of sensory neuropathy are suspected to affect also shorthaired pointers, English pointers, longhaired dachshunds, and a Jack Russell terrier. Cases of acquired sensory neuropathies have been described in a Siberian husky, Doberman, whippet, Scottish terrier, and a golden retriever.
Characteristics and symptoms
Affected dogs start to show symptoms between the ages of 5 and 7 months. Clinical signs include loss of coordination, joint laxity, loss of proprioception (lack of awareness where the limbs are in space), and inability to perceive pain. Affected dogs often have self-mutilated limbs, which may be due to tingling or pain in their paws, another manifestation of the disorder. Since the disorder is progressive and the symptoms are severe, affected dogs are usually euthanized.
Sensory neuropathy in Border collies is caused by a mutation in FAM132B gene, which encodes a Golgi protein found in sensory and autonomic ganglion neurons. The complete role of this gene remains unclear, but it has been confirmed that the gene is crucial in the survival of the sensory nerve cells.
The disorder is inherited in an autosomal recessive pattern. A dog can be clear, carrier or affected. Carriers of the gene are heterozygous and do not develop the disease’s symptoms. When mating two carrier dogs, each future cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
Forman OP, Hitti RJ, Pettitt L, Jenkins CA, O’Brien DP, Shelton GD, Risio LD, Quintana RG, Beltran E, Cathryn Mellersh. An inversion disrupting FAM134B is associated with sensory neuropathy in the Border Collie dog breed. G3 (Bethesda). 2016 Sep 8;6(9):2687-92.