Paroxysmal dyskinesia in Shelties

Paroxysmal dyskinesia is an episodic movement disorder. Triggers can be, for example, physical exertion, stress or heat. During an episode, we observe impaired coordination of movements, increased muscle tone, cramps, slight tremors or even limited mobility.

In Shelties, this disease is associated with a missense mutation c.1658G>A in the PCK2 gene encoding mitochondrial phosphoenolpyruvate carboxykinase 2. Mutation disrupts energy metabolism and, in combination with physical exertion or other triggers, can lead to impaired movement control.

It is assumed that the mode of inheritance of the mutation is autosomal dominant, but due to the dependence of the manifestations of the disease on external factors (triggers), it is possible that some individuals with a mutated copy of the disease might not show any symptoms at all.

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References:

Nessler, J., Hug, P., Mandigers, P.J.J., Leegwater, P.A.J., Jagannathan, V., Das, A.M., Rosati, M., Matiasek, K., Sewell, A.C., Kornberg, M., Hoffmann, M., Wolf, P., Fischer, A., Tipold, A., Leeb, T. : Mitochondrial PCK2 missense variant in Shetland Sheepdogs with paroxysmal exercise-induced dyskinesia (PED). Genes (Basel) 11:774, 2020. Pubmed reference: 32660061