[GoLightly]

I used to think mtDNA came from the X of the XX/XY pair, as I knew it was inherited from our maternal side.

I try not to use Wiki for a resource too much, but when something isn't politically charged it can be useful...

http://en.wikipedia.org/wiki/Mitochondrial_DNA

[Fred Nerks]

Mutations of mitochondrial DNA can lead to a number of illnesses including exercise intolerance ----

My mitrochondrial DNA has definitely been mutated!

thanks for the link.