For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.
At risk dogs are likely to show signs of this disease in their lifetime.
Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.
Limb-girdle muscular dystrophies are a group of inherited disorders which lead to progressive muscle dysfunction. The group is characterized by muscle weakness which, in dogs, has a tendency to affect muscles of the shoulders and hips. This variant in the SGCD gene, first discovered in the Boston Terrier, is associated with clinical signs beginning between 2 to 4 months of age. Initial signs can include muscle atrophy and a stiff, short-strided gait. Affected puppies may also show drooling or dysphagia (difficulties swallowing), regurgitation, and have an abnormally large tongue. While the muscle atrophy is thought to be non-painful, the disorder is progressive and may cause severe discomfort over time. Affected dogs are often euthanized before 1 year of age due to welfare concerns.
As there is no cure for this disorder, therapy is limited to symptomatic treatments and general supportive care. Due to the progressive nature of LGMD, the average long-term prognosis is considered poor for affected dogs.
There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.
This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Limb-girdle Muscular Dystrophy (Discovered in the Boston Terrier) variant can be safely bred with a clear dog with no copies of the Limb-girdle Muscular Dystrophy (Discovered in the Boston Terrier) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disorder signs similar to the ones associated with this Limb-girdle Muscular Dystrophy variant could develop due to a different genetic or clinical cause.
Cox, M.L., Evans, J.M., Davis, A.G., Guo, L.T., Levy, J.R., Starr-Moss, A.N., … Shelton, G.D. (2017). Exome sequencing reveals independent SGCD deletions causing limb girdle muscular dystrophy in Boston terriers. Skelet Muscle, 7(1), 15. View the article