Acral Mutilation Syndrome
Affected Genes: GDNF
Inheritance: Autosomal Recessive
Variant(canFam6):
chr4:70550050: C>T
Breed: Cockapoo
Cocker Spaniel
Deutsch Kurzhaar
English Cocker Spaniel
English Springer Spaniel
French Spaniel
German Shorthaired Pointer
Old English Sheepdog
Pointer
Sheepadoodle
General Information: Acral Mutilation Syndrome (AMS) is a genetic neurological disorder affecting dogs, typically presenting around 4 months of age. Affected dogs exhibit insensitivity to pain in their lower limbs, leading to repetitive licking and biting of their paws, which often results in severe self-mutilation. These dogs are usually smaller than their littermates and suffer from severe self-induced wounds on their feet, including toe amputations, loss of toenails, and bone fractures. Secondary infections can complicate these open wounds. Since affected dogs cannot feel pain in their feet, they continue to walk without obvious discomfort. Due to the lack of treatment options and significant quality of life concerns, euthanasia is often considered by owners and their veterinarians.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Unlikely Affected
No Variants Detected: No Effect
Gene / Testing Information: Genetic testing for Acral Mutilation Syndrome (AMS) involves screening for mutations in the GDNF gene to determine carrier status. This disorder is inherited in an autosomal recessive manner, meaning a dog must inherit two copies of the mutated variant, one from each parent, to be at risk of developing the disease. However, AMS may exhibit incomplete penetrance, meaning that some dogs with two copies of the GDNF mutation may not develop the disease. Carriers do not typically exhibit symptoms but can pass the variant on to their offspring. When two carriers are bred, each puppy has a 25% chance of inheriting two copies of the mutation (at risk for the disease) and a 50% chance of being a carrier. To prevent producing affected puppies and eliminate the mutated variant from breeding lines, it is crucial to avoid breeding two carriers. Genetic testing is essential before breeding to ensure responsible practices. Dogs that are not carriers of the this variant do not pose a risk of producing affected puppies.
References:
Cummingss JF, de Lahunta A, Winn SS. Acral mutilation and nociceptive loss in English pointer dogs. A canine sensory neuropathy. Acta Neuropathol. 1981 53(2):119-27.
Plassais J, Lagoutte L, Correard S, Paradis M, Guaguere E, Hedan B, Pommier A, Botherel N, Cadiergues M, Pilorge P, Silversides D, Bizot M, Samuels M, Arnan C, Johnson R, Hitte C, Salbert G, Mereau A, Quignon P, Derrien T, Andre C. A Point Mutation in a lincRNA Upstream of GDNF Is Associated to a Canine Insensitivity to Pain: A Spontaneous Model for Human Sensory Neuropathies. PLoS Genet. 2016 12(12):e1006482.