Congenital Myasthenic Syndrome (Jack Russell Terrier Type)

General Information: Congenital Myasthenic Syndrome (CMS) (Jack Russell Terrier Type) is a genetic neuromuscular disease that manifests in young dogs, typically around 6 to 7 weeks of age. Dogs with this condition experience severe exercise-induced weakness, leading to collapse. During episodes of weakness, affected dogs exhibit decreased reflexes in all limbs and a progressively worsening short-strided gait until they are unable to continue moving. These symptoms resolve with rest, allowing the dogs to return to a normal state between episodes. However, due to the severity of the condition and the lack of effective treatments, affected puppies often face significant health challenges and may be humanely euthanized within a few months.

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 Congenital Myasthenic Syndrome (Jack Russell Terrier Type) involves screening for mutations in the CHRNE gene. This disease follows an autosomal recessive inheritance pattern, meaning that a dog must inherit two copies of the mutated gene (one from each parent) to develop CMS. Carriers, which have one copy of the mutation, do not show symptoms but can pass the gene to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected and a 50% chance of being a carrier. Genetic testing is crucial for responsible breeding practices, allowing breeders to identify carriers and avoid pairing them, thus reducing the risk of producing affected puppies. By ensuring that at least one parent in a breeding pair does not carry the mutation, breeders can help prevent the transmission of this debilitating condition and promote healthier litters.