mtDNA

Mitochondrial DNA (mtDNA) is inherited mainly unchanged from mother to child. Thus it follows our direct maternal line, through women only, following the line back through your mother’s mother’s mother’s mother … – and follows the matriline. mtdna

Everyone has got mtDNA and can get it tested, but only women bring it on to their children.

Maternal line mtDNA

mtDNA-tests can be used in two ways:

Genealogy:
– find matches among people who have almost identical mtDNA and accordingly a common ancestor in the direct maternal line. This method can be used to test several people descending from the same woman through women only, to verify traditional genealogy.

  • We recommend mtDNA FMS, full sequence test
  • As control of an already tested line a smaller test may be enough (HVR)
Tre etterkommerlinjer testet

Three descendent lines tested through mtDNA

Antropology:
– show which mt-haplogroup one belongs to, e. g. H1, U5 or T2 which are the three most common ones in Norway.

Test types for mtDNA

There are several different mitochondrial tests on the market, where the difference  is how much of the mitochondrial DNA they analyze.

  • HVR1: base pairs 16001-16569 (FTDNA no longer offer this one)
  • HVR1 + 2: base pairs 00001-00574 + HVR1, price $59 at FTDNA
  • Full Genome Sequence (FMS): all 16569 base pairs, price $199 or less, dependent on sales and campaigns

HVR-tests will give a rough estimate of main haplogroup, while FMS (full sequence) gives you the final complete results and haplogroup with subclade. Subclade might not always be defined by scientists yet, read more.

Mitochondrial_DNA_en.svg

The HVR region is also called Control Region or D-loop. The rest is the Coding Region.

The only complete test that will assign you with certainty to your haplogroup and subgroup is the Full Sequence test FMS, because most of the mutations that define the different subgroups are placed in the Coding Region.

Short overview

  • FMS-tests is what is normally required to find matches relevant for genealogy
  • Verifying genealogy is about testing at least two people with the same direct maternal ancestor to control if the paper trail is correct, that the two have identical (or almost identical) result
  • Simple tests (HVR1/HVR2) will give you haplogroup («ancestral mother») while matches can go back ten thousans of years to a common ancestor
  • different haplogroups give very different results and number of matches
  • the matches worth contacting are the FMS matches with max 0-2 steps off

A simple HVR-test might still be useful for your genealogy, if applied as control test to verify already tested lines. If there is no match at HVR level and the control test is in another haplogroup, the two testees will not have the same direct maternal ancestor. Our genealogy work will have to be revised.

mtDNA as genealogical method

The Norway project has published articles (in Norwegian only for now) on mtDNA-testing applied in genealogy. (Use Google translate for an idea; translations are planned.)

Who should we test?

As a woman your own mtDNA can be analysed. Your brother, your maternal uncle and your son will also represent your direct maternal line and have the exact same mtDNA as yourself. Either of these three will normally be a better choice for submitting a sample than yourself, since you will then also have the opportunity to also do a Y-DNA-analysis on the sample at the same time, or later as an add-on. Read more here.

mtDNA as genealogical source

Ideally all living mtDNA-lines in Norway should be tested and documented.

Result lists for mt-tests in our project are easily available for genealogists on the Norway DNA results list pages, with information about the earliest known direct maternal ancestor for the person tested. (Name and data for who the living tester is will not be listed anywhere to ensure privacy.)

This result list can be viewed as a genealogical source. The quality of the source increases as we verify lines through control testing.

mtDNA Haplogroups

There are many mt-haplogroups (not to be mixed up with Y-DNA haplogroups), and for people with European ancestry there are about twelve different ones. One of these, H, includes about half of all people with European ancestry.

The different haplogroup definitions can be found in the phylotree, which is updated regularly with new research.

Have you done the Full Mitochondrial Sequence (FMS)? Are you still “just” H, V, T2 – or other udefined groups? Maybe no one has done any research on just your specific mtDNA mutations yet. Please consider donating your mt-sequence to research so that it can be studied before the next larger updates to the mt-tree and name definitions.

More about the mt-haplogroups here (Norwegian only).

Matches and Results

The Full Sequence test (FMS) is an analysis of all 16569 base pairs of the mtDNA, and it necessary to use mtDNA-testing for genealogy. The reason for this is that mtDNA change very slowly, so a person you match with 1 or 2 mutations different (genetic distance) will share a common maternal ancestor with you, but it might be thousands of years back.

Read about which matches to contact to compare ancestry.

Treff (rød) og resultat (gul)

Click Matches (red) to see the list of your matches. Click Results (yellow) to show the list of your mutations and haplogroup.

Matches at full sequence FMS level, people with identical (GD 0) or nearly identical (GD of 1-2) mitochondria with you:

  • you will share a common direct maternal ancestor who could have lived from more recently to a few thousand years ago – use genealogy to decide
  • systematic testing is recommended to verify female lines by control testing other descendants in the same maternal line
  • haplogroup with detailed subgroup is normally established

Testing HVR (1 og 2):

  • a match at HVR-level only means you descend from the same «ancestral mother» – about 12 different ones known in Europe
  • the common direct maternal ancestor could have lived many thousand years ago
  • the main haplogroup is known, perhaps an indication of subgroup

Consequently: to use mtDNA for genealogical purposes, the FMS test is usually necessary.

Study Family Tree DNA’s FAQ page on mtDNA results to learn more.

What is mtDNA?

Your mitochondrial DNA is only a tiny part of your genetic make-up. Typically our mtDNA haplogroup reveals our ancestry in the direct maternal line some 5000-50 000 years back. If you look at your full ancestry tree, this is just the thin line at the very end of the ancestral fan, following the mothers only. Imagine how tiny a portion of your ancestry this is 5000 years ago.

Thus an mtDNA-test can only tell you something about this tiny, narrow line.

If you wish to have an estimate of your ethnic origin, try the extensive autosomal test Family Finder, which test some 700 000 SNPs across your autosomes, and gives you ethnic breakdown through the MyOrigins function.

What can my mtDNA test not tell me?

Eye, hair and skin colour, what food you can eat and not, how tall you are, your blood type: all these traits are decided by several genes on your autosomes, and not your mitochondrial DNA.

mtDNA from Geno 2.0 or 23andMe?

Geno 2.0 will assign you to your haplogroup and a subclade (not final). It does not analyse the the full HVR-region which is what is shown on project pages. Thus the test results will not appear in the public project lists of tested maternal lines in Norway – or other projects you join. In general Geno 2.0 is not recommended for female testees since most of the analysis done in this test focus on the Y-chromosome, which women do not have.

If you have an older Genographic test, this is an analysis of the HVR1-region, and we hope you will join!

23andMe offers one type of test only, which include an analysis of about 2500-3000 SNPs on the mitochondria. This will often be enough to find out haplogroup and a few subgroups, but it is not a complete test, and it does not easily compare with tests from other companies, as the SNPs tested are spread over the mtDNA. If you already have an mtDNA-test from 23andMe, only the Full Sequence at FTDNA (all 16569 SNPs) will be useful to learn more. If you have a Norwegian direct maternal line and 23andMe-results we can add you to our Local projects, just send us an email with information about your line and your results. The raw data file from 23andMe can also be uploaded to the mthap online tool by James Lick, to find out which SNPs/mutations you have.

“Fast Mutators”

There are a few SNPs that are considered to mutate frequently, and it can be useful to disregard these when comparing results. The list is found on phylotree, above the actual tree structure.

The SNPs disregarded in phylogeny are:

  • 309.1C(C)
  • 315.1C
  • 523-524d (aka 522-523d)
  • 16182
  • 16183C
  • 16193.1C(C)
  • 16519

In general a Full Sequence test is necessary to use mtDNA for genealogical purposes. A “simple test”, HVR normally only gives you your haplogroup and the “long lines”.

Links

ISOGG: Comparison table of mtDNA-tests (from ISOGG wiki)

 

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