Ullrich Congenital Muscular Dystrophy (Labrador Retriever Type 2)
Affected Genes: COL6A3
Inheritance: Autosomal Recessive
Variant(canFam6):
chr25:48505344: C>T
Breed: Australian Labradoodle
Labradoodle
Labrador Retriever
General Information: Ullrich Congenital Muscular Dystrophy (Labrador Retriever Type 2) is an inherited muscle disease affecting Labrador Retrievers and related breeds. This condition is typically diagnosed around 3 to 4 months of age. Affected dogs exhibit noticeable limb deformities and hyperflexion of the joints, particularly at the wrist (carpus) and ankle (hock), resulting in a flatfooted stance. Over time, dogs may develop muscle atrophy and display an abnormal gait. The disease progresses slowly, and while dogs can live for many years with the condition, the severity can eventually lead to humane euthanasia due to compromised quality of life. Affected dogs require careful management to maintain mobility and comfort throughout their lives.
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 of the COL6A3 gene will indicate whether a dog is a genetic carrier of Ullrich Congenital Muscular Dystrophy (Labrador Retriever Type 2). This disorder is inherited in an autosomal recessive manner, meaning that a dog must inherit two copies of the mutated gene (one from each parent) to develop the disease. Dogs with only one copy of the mutation are carriers and typically do not show symptoms but can pass the gene to their offspring. If two carriers are bred, each puppy has a 25% chance of developing the disease and a 50% chance of being a carrier. Reliable genetic testing is crucial for breeders to identify carriers and make informed breeding decisions to prevent the birth of affected puppies. It is important to note that while genetic testing can identify carriers of this specific mutation, it does not rule out the possibility of other genetic mutations that could cause similar disorders. Therefore, comprehensive genetic screening is recommended to ensure the health of breeding lines and future generations.
References:
Bolduc V, Minor KM, Hu Y, Kaur R, Friedenberg SG, Van Buren S, Guo LT, Glennon JC, Marioni-Henry K, Mickelson JR, Bönnemann CG, Shelton GD. Pathogenic variants in COL6A3 cause Ullrich-like congenital muscular dystrophy in young Labrador Retriever dogs. Neuromuscul Disord. 2020 30(5):360-367.
Marioni-Henry K, Haworth P, Scott H, Witte P, Guo LT, Shelton GD. Sarcolemmal specific collagen VI deficient myopathy in a Labrador Retriever. J Vet Intern Med. 2014 28(1):243-249.