You have the same mDNA as any of your maternal siblings, your mother, and your mother’s siblings, as well as your cousins by your mother’s sisters, and your mother’s mother-- you get the idea. So if you are a man looking to clone yourself, and you want the clone to have your mDNA, you need an ovum from your sister, your mother, your girl cousin by your mother’s sister, etc. Some people might find that squicky.
When I brought up the issue, I had no idea whether or not mDNA was a factor in organ rejection; if it’s not, no worries.
People love to bring up mtDNA in discussions like this, because it’s so oddball, but the fact is that it’s a tiny, tiny chunk of DNA compared to the nuclear DNA, and only contains a few handfuls of genes that only matter to the mitochondria themselves. For all practical purposes, it can be safely ignored.
Well, it’s also useful for study. You can learn interesting things about the ancestry of an organism or group of organisms by looking at the mtDNA. Or, in this case, one might be able to distinguish between a clone and the original, if that were something that one cared to do.
Yes, those are both legitimate and valid reasons to care about mtDNA. I’m just saying that outside of those specialized contexts, people tend to bring mtDNA up a lot when it’s not really relevant.