First of all, what’s mitochondrial DNA testing? Mitochondrial DNA testing (mtDNA testing) compares the mitochondrial DNA of a tester with that of anyone taking the same test. As with other tests, the tests compare only certain regions of the DNA in order to estimate an approximate relationship. As of right now, only FamilyTree DNA offers the test.
Why take the test at all? Until 2018, mitochondrial DNA commonly believed to be inherited only from the mother. It’s now known that some people can inherit mitochondrial DNA from both parents, but as those cases are relatively rare, mtDNA testing is still seen as an effective way to investigate the maternal side.
Do lineage societies accept mtDNA? No. Mitochrondrial DNA mutates slowly, making it difficult to identify a “common ancestor” for matches. According to Family Tree DNA’s “Help Center”, a perfect match on their most extensive test has a 50% chance of having a common ancestor in the last 125-400 years. Because it cannot be used to identify a specific common ancestor, mtDNA is not accepted for lineage society applications.