Central Core Myopathy (Centronuclear myopathy) in Dogs
What is central core myopathy?
Central Core Myopathy is an autosomal (not sex-linked) recessive, inherited, non-painful, centronuclear myopathy (muscle disease) associated with a particular defective section on a specific gene (BIN1 gene) in Great Danes. Most affected dogs start to show symptoms by six months of age. The central part of the skeletal muscle cells (muscles that move the body) is abnormal. Nerve function in these dogs is completely normal. Because it is a recessive genetic disease, apparently normal dogs can carry the disease and pass it on to their puppies if mated with another dog carrying the abnormal gene.
What are the symptoms/signs of central core myopathy?
Symptoms include generalized skeletal muscle weakness, especially of the rear legs, leading to a crouched stance when walking and muscle atrophy (decrease in muscle size). Due to severe muscle weakness, these dogs will have exercise intolerance and are prone to collapse.
What causes central core myopathy?
Central core myopathy is caused by a genetic defect in the AMPH section of the BIN1 gene. This mutation leads to abnormal amphiphysin protein being produced that is important for normal skeletal muscle function. These abnormal proteins affect the central section of the muscle cells and lead to loss of function.
How is central core myopathy diagnosed?
Affected dogs will have relatively normal complete blood counts and serum chemistry results except for elevated creatine kinase levels. Creatine kinase is a muscle enzyme which is elevated with muscle damage/inflammation. Thus we often see elevated levels with myopathies. Central core myopathy can only be definitively diagnosed via a muscle biopsy showing characteristic changes to the muscle cells and/or mutational analysis of the BIN1 gene in an affected dog. The abnormal gene can be identified via genetic testing, but that test is not yet readily available through most laboratories. However, this disease is similar to one found in Labrador Retrievers, and there is testing available through one laboratory that tests Labradors for their myopathy.
The dog’s breed, symptoms, and multiple puppies being affected in one litter may lead to a tentative diagnosis, and should alert breeders not to breed the parents again before genetic testing is done.
What are treatment options for central core myopathy?
As of now, there is no effective treatment for central core myopathy. We can control the symptoms and keep them more comfortable by not pushing them to exercise beyond their tolerance and limiting stress and excitement. Some veterinarians recommend supplements such as Coenzyme Q-10, but none have proven efficacy.
Humans also have been diagnosed with a similar, although definitely different, type of central core myopathy and perhaps research will lead to drug treatment that may be beneficial across the two species.
What is the prognosis of central core myopathy?
An affected dog’s prognosis will depend on upon how severely he/she is affected and the owner’s willingness to modify their lifestyle. These dogs are unlikely to have a normal lifespan, but some mildly affected dogs can do well for years. Severely affected dogs have a very poor quality of life and in those cases, many owners may choose humane euthanasia.
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About the Author:
Dr. Kara has been an Expert on JustAnswer since 2010 with over 12,943 satisfied customers.
Dr. Kara graduated from Michigan State University. She is a member of the American Veterinary Medical Association, (AVMA), has over 20 years of experience in practicing small animal and pocket pet medicine. With emphasis on preventative care, internal medicine, and behavioral issues, Dr. Kara is also active with Greyhound rescue. While rescuing Greyhounds as pets, she strives to work with owners to tailor a plan to fit their personal lifestyle while minimizing the risk of exposure to disease for the pet.
Her interests and hobbies include international travel, hiking, reading, spending time with her husband and two children.