From what I've read, MS isn't technically inherited (in the way Cystic Fibrosis is, for example) but having a family member makes one statistically more likely than average.

That said, my father had MS. My aunt and I have wracked our brains trying to remember some relative who had symptoms but might have gone undiagnosed, but we can't.

I worry every time my son says he's "really exhausted" or my daughter clumsily stubs her toe. But then, that's me.