Deep Into DNA
a monthly column by Mike Maglio
Your mother’s ancestry can be extremely challenging. Most of us live in a patrilineal society. The wife and the children take the surname of the husband. History shows us that recording the maiden name of the wife was often an afterthought. We have all tried traditional genealogy for our mother’s line. Some of us can go back a couple of generations and have hit brick walls. Some of us have researched a dozen generations. Mitochondrial DNA testing can aid a genealogist in discovering those lost surnames and validating your research.
Two months ago, I wrote about y-DNA and its use in tracing your paternal line. Mitochondrial DNA testing looks at your maternal line. There are many similarities and just as many differences between the two tests.
Y-DNA comes from one chromosome in male DNA and is passed only from father to son. Mitochondrial DNA comes from within our cells and is passed from mother to all of her children. Mt-DNA has its own DNA and should not be confused with x-DNA. Both y-DNA and mt-DNA are inherited virtually unchanged. This allows us to trace our ancestors back hundreds of generations. Y-DNA has a higher rate of mutations and more variation. Mt-DNA has a lower rate of mutation and is considered more stable.
Both men and women can be tested to learn about their maternal line. A mitochondrial DNA test looks at up to 16,569 base pairs. There are 545 base pairs in HVR1 (Hyper Variable Region 1), the most basic test. The HVR1 test will give you deep ancestral information and identify genetic matches to about 60 generations ago. Adding the HVR2 (Region 2) test and 576 more base pairs reduces the genetic distance to 30 generations between two exact matches. The full mitochondrial sequence, all 16,569 base pairs, gives you a 75% chance of matching within 21 generations and a 50% chance of matching within 7 generations. Start with a test that works for your budget and then upgrade if you find many matches. The goal is to find a match and then rely on traditional genealogy to fill the generation gap.
The first published mitochondrial DNA test is from a European individual and is called the Cambridge Reference Sequence (CRS). All mt-DNA tests results are in relation to the CRS. My HVR1 results look like this - 16311C, 16519C. That’s it. I have two mutations within my HVR1 and three within my HVR2 in comparison to the Reference. We are both haplogroup H. More than likely, I share a common ancestor with the CRS over 5,000 years ago, but probably closer to 10,000 years ago.
No matter how many DNA regions you test, as a minimum you will learn about your world origins, your haplogroup. There are roughly twenty-six world mt-DNA haplogroups designated A through Z. Each haplogroup has an approximate geographic origin and ethnic identity. A haplogroup is defined by unique mutations. These mutations are called an SNP, a single nucleotide polymorphism. There are additional mutations that can define subgroups within a haplogroup. Only a SNP test can confirm that you belong to a subgroup.
If there is an oral tradition in your family that you are Native American along your maternal line, now is your chance to prove it. The Native American haplogroups are A, B, C, D and X. Here are some other approximate ethnic connections-
If you already have a significant traditional genealogy for your maternal line with a dozen generations, you can use mt-DNA to confirm your research. Genealogists researching the same ethnic group may form a geographic group or society. Many of these groups already have DNA projects running with many participants. Examples include Acadian and Melungeon projects. Compare your DNA to the DNA of two or more parallel maternal lines, the results can prove or disprove your research. In the event that a DNA project doesn’t exist matching your ethnic or geographic research, you can start one and invite other genealogists to join.
You might only have a few generations documented and now you are stuck. Mt-DNA can open new avenues of research by putting you in touch with genetic cousins. After testing, you will find matches that have the potential of taking you around your brick wall. If your genetic cousin has researched further back in time to a common ancestor, then you could work forward in time from there to make the connection to your line.
Mitochondrial testing has made the headlines on many occasions. There have been many success stories about the identification of remains of American armed forces personnel who failed to return. An mt-DNA test from a mother or a sibling as a reference sample can prove an identity.
Mitochondrial DNA tests are not inexpensive. They range from $160 for a combined HVR1+HVR2 test to $300 for the full sequence. You may want to start with the lesser test. If you receive many exact matches, then you have the option of upgrading your test to the full sequence to refine your genetic relationship. If you have no exact matches, then upgrading will not improve your chances. In time, more records will be added to the databases and your testing company will send you an email if you get a new match.
You don’t have to settle for just your mother’s line, you could also test your father to get his mother’s line. You may be able to find a female descendant to test for every maternal surname in your tree. Think about collecting DNA samples from the older generations in your family.
As far as DNA tests go, I don’t like to pick favorites. Use a top laboratory, even if it costs a bit more. As they say – “You get what you pay for.” Family Tree DNA is a world leader. They have the largest database of results and the best selection of quality tests. DNA results are just another piece of data and many of the best genealogy software products allow you to add your DNA results to your family records. When you do create your mt-DNA record, you will have an opportunity to enter your most distant maternal ancestor. When possible, also enter family tree information or all the maiden names. The notes on my record look like this – Krause>Schulz>Merke>Albig>Hess.
Whatever your reasons may be, finding your deep ancestral origins, verifying your traditional genealogy or breaking through brick walls, mt-DNA is a great tool to add to your research kit.
© Mike Maglio 2012
This article originally appeared in the October 2012 issue of The In-Depth Genealogist. Receive The In-Depth Genealogist free by subscribing HERE.