Congenital Myasthenic Syndrome Recently Identified in Golden Retriever Puppies

Drs. Karen M. Vernau and G. Diane Shelton
University of California Davis and University of California San Diego



Figure 1: Twelve week old male Golden Retriever puppy with poor exercise tolerance since 8 weeks of age. Following just a few steps the puppy would collapse and assume the position in the image

Clinical History on 14 week old female Golden Retriever
A 14 week old female Golden Retriever was presented to the UC Davis VMTH Neurology/Neurosurgery Service for further evaluation of generalized weakness.. At 8 weeks of age, the puppy developed an abnormal shifting leg lameness and gradually became less active. After a burst of energy the puppy would sit or lie down.

No abnormalities were noted on physical examination. On neurological examination, abnormalities were restricted to an abnormal gait. The puppy was ambulatory with a pacing gait, that became shorter and stiffer as the puppy walked, to the point where the puppy would lie down. The puppy appeared to tire easily and sat down often during the examination.

The clinical signs were most consistent with a generalized neuromuscular disease, caused by a neuropathy, myopathy or disorder of neuromuscular transmission. Based on the young age, a congenital or metabolic disorder was considered most likely.

A Congenital Myasthenic Syndrome was Confirmed by Candidate Gene sequencing
In collaboration with Dr. Leigh Anne Clark at Clemson University, a mutation was identified in COLQ, the gene encoding the collagenous tail of acetylcholinesterase. The mutation is different from that affecting Labrador Retrievers with CMS (Click to read Labrador Retriever paper in PLoS One).

We are trying to identify additional affected Golden Retriever puppies and unaffected littermates
If you are a veterinary clinician and aware of any affected puppies, please contact Dr. Diane Shelton ( Genetic testing is available for puppies that fit this clinical description. A scientific manuscript is in preparation.





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