Centronuclear Myopathy
Affected Genes: PTPLA
Inheritance: Autosomal Recessive
Variant(canFam6):
chr2:16473570: 13 bp dulication CACACAAAGGTTT
Breed: Australian Cobberdog
Australian Labradoodle
Lab/Golden Cross
Labradoodle
Labrador Retriever
Service/Assistance Lab/Golden Retriever cross
Service/Assistance Labrador Retriever
UK Breed Council Labrador Retriever
General Information: Centronuclear Myopathy (CNM) is a hereditary progressive muscle disorder predominantly seen in Labrador Retrievers. Symptoms vary in intensity but commonly include exercise intolerance, an awkward gait, and feeding difficulties emerging within the first few months of life. As the condition advances, dogs may experience widespread muscle wasting, a tendency for the head and neck to droop downwards, reduced muscle tone, and an increased likelihood of collapsing in cooler temperatures. The progression of CNM generally stabilizes by the time the dog reaches one year of age. While affected dogs tend to live a normal lifespan, they often face ongoing health issues related to their muscular condition.
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 Centronuclear Myopathy (CNM) is conducted through analysis of the PTPLA gene, which can indicate the presence of the genetic variant responsible for this condition. CNM is inherited via an autosomal recessive pattern, meaning a dog must inherit two copies of the mutated gene, one from each parent, to exhibit symptoms of the disease. Carriers, possessing only one copy of the mutation, do not show symptoms but can produce affected offspring if bred with another carrier. Each puppy from such a pairing has a 25% chance of being affected by CNM. It is crucial for breeders to use reliable genetic testing to guide breeding decisions; breeding carriers together is strongly discouraged to prevent perpetuating the condition. Dogs identified as non-carriers do not have an increased risk of producing affected offspring, thereby helping to reduce the prevalence of CNM in future generations. A normal test result for the PTPLA gene mutation does not rule out other potential genetic disorders that may cause similar symptoms, indicating the need for comprehensive genetic screening in breeding practices.
References:
Gentilini F, Zambon E, Gandini G, Rosati M, Spadari A, Romagnoli N, Turba ME, Gernone F.Frequency of the allelic variant of the PTPLA gene responsible for centronuclear myopathy in Labrador Retriever dogs as assessed in Italy. J Vet Diagn Invest. 2011 23(1):124-126.
Maurer M, Mary J, Guillaud L, Fender M, Pele M, Bilzer T, Olby N, Penderis J, Shelton GD, Panthier JJ, Thibaud JL, Barthelemy I, Aubin-Houzelstein G, Blot S, Hitte C, Tiret L. Centronuclear myopathy in Labrador retrievers: A recent founder mutation in the PTPLA gene has rapidly disseminated worldwide. PLoS One 2012 7(10):e46408.
Pelé M, Tiret L, Kessler JL, Blot S, Panthier JJ. SINE exonic insertion in the PTPLA gene leads to multiple splicing defects and segregates with the autosomal recessive centronuclear myopathy in dogs. Hum Mol Genet. 2005 14(11):1417-1427.