How does the mutant DNM1 gene cause EIC?
The DNM1 gene produces a protein called dynamin 1 that functions in communication between neurons in the central nervous system, and between the motor neuron and the muscle fiber at the neuromuscular junction. It is known that mice with no functional DNM1 gene or dynamin 1 protein at all die soon after birth. Therefore, we hypothesize that the DNM1 gene mutation found in EIC susceptible dogs causes a somewhat diminished function (but not a complete lack of function) of the dynamin 1 protein in the brain and nerve fibers. It is likely that carrier dogs, which would have both the E and the N forms of the dynamin 1 protein in their neurons, have enough functional dynamin 1 to ensure neural function in all situations. Even E/E dogs that produce only the E form of the protein function normally under non-stressful situations. This supports the idea that the EIC form of the protein works sufficiently well to enable normal nerve communication during mild to moderate activity. However, we also
