Nope. The ability to diagnose it is pretty new; it went undiagnosed in my oldest sibling until age 12 or so. Not for lack of trying; they just couldn't figure out what it was until then. The effects vary wildly based on where the "bad" mitochondria are distributed throughout your organs, so there's no one thing to look for. Even though she carries it, my mother didn't develop any symptoms herself until well after her children did.

She once told me she wouldn't have had children if she'd known she carried it. I'd make the same choice if I were female.