IIRC (and my brother and my best friend are both epileptic, so I know a little about the condition), epilepsy is not a heritable condition; it's caused by damage to the brain (often, but not always, at birth). So it is not reasonable to think that your father might have epilepsy just because one or more other people in the family have.

I'm glad to hear that, whatever caused his seizure, he's okay now.