Early-Onset Epilepsy (Parson Russell Terrier Type)

Common Symptoms

Early-Onset Epilepsy (Parson Russell Terrier Type) is an inherited neurological disease affecting dogs. Dogs affected with this type of epilepsy present between 8 and 10 weeks of age with frequent, uncontrolled seizures. This form of epilepsy is rapidly progressive and typically not responsive to treatment. Affected dogs die or are euthanized within a few days of disease onset.

Testing Tips

Genetic testing of the PITRM1 gene in dogs will reliably determine whether a dog is a genetic Carrier of Early-Onset Epilepsy (Parson Russell Terrier Type). This disease is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the PITRM1 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.

There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.

References

• Hytönen, M.K., Sarviaho, R., Jackson, C.B. et al. In-frame deletion in canine PITRM1 is associated with a severe early-onset epilepsy, mitochondrial dysfunction and neurodegeneration. Hum Genet 140, 1593–1609 (2021). https://doi.org/10.1007/s00439-021-02279-y