Our Three Basic Tests

We offer three basic types of tests: Family Finder (autosomal DNA), Y-DNA, and mitochondrial DNA (mtDNA). Note: Click on the blue boxes () below for information on […]

What is the geographic and historic origin of my mitochondrial DNA (mtDNA) haplogroup?

The following descriptions provide brief overviews of each main mtDNA haplogroup’s origin and geographic distribution. Haplogroup A Haplogroup A is found in eastern Eurasia and […]

How do I know which of my heteroplasmic values is ancestral (original) and which is derived (new)?

To find which version of a heteroplasmic mitochondrial DNA (mtDNA) result is original and which is newer, you need to test other descendants of your […]

From which “Daughter of Eve” do I descend?

The Daughters of Eve are named after some of the major haplogroups, but the names are arbitrary. The names usually begin with the same letter […]

How do I tell how closely I am related to a mitochondrial DNA (mtDNA) match?

The closeness of a mitochondrial DNA (mtDNA) match depends on the matching level. Matches at higher levels are more likely to be recent. The table […]

How do I find the genealogical connection with my mtDNA match?

The only way to find a connection with your match is by comparing your genealogies. In many cultures, women changed names with marriage. Therefore, it […]

Are there exceptions to the alphanumeric naming of mitochondrial haplogroups?

Yes. There are two exceptions to the alphanumeric naming of mitochondrial haplogroups. The first is the use of a zero (0) in the name to indicate […]

Will my mitochondrial DNA (mtDNA) results show me admixture percentages for ancestry from different lines?

No, because mitochondrial DNA (mtDNA) is inherited exclusively from your direct maternal line, it does not show admixture from your other lines. That is, you […]

How common is mtDNA heteroplasmy?

All mitochondrial DNA (mtDNA) mutations go through a state of heteroplasmy. The frequency of heteroplasmy is then equal to or greater than mtDNA mutation rates. […]

How is mtDNA heteroplasmy inherited?

In each generation, it is possible for the child to inherit the heteroplasmic genome, only the ancestral genome, or only the descendant genome. For each […]

How do mitochondrial mutations occur?

Every human cell contains hundreds of mitochondria. Each mitochondrion in a cell contains multiple copies of its own DNA (mtDNA). A new mitochondrial mutation occurs […]

Where can I share information with others who have mtDNA tested?

There is an mtDNA section in Family Tree DNA’s Forums.

How do I use mtDNA (mitochondrial DNA) to help with my recent genealogy?

To find connections in recent times, it is necessary to find and test multiple people who have suspected shared ancestry. You can do this by […]

Are all of a mother’s new mitochondrial DNA (mtDNA) mutations inherited by children?

No. Mothers only pass on those mitochondrial DNA (mtDNA) mutations they inherited from their mothers and new mutations that occur in their eggs. Mutations that […]

Do all direct maternal (mitochondrial DNA) lineages trace to Africa?

Yes so far, all direct maternal (mitochondrial DNA) lineages of women alive today trace back to a common ancestor who lived in Africa 100,000 to […]

How does the formation of the human egg cell change the frequency of an mtDNA heteroplasmic mutation?

At one point during the process by which the egg cell is produced (oogenesis), the number of mitochondria present in the cell is dramatically reduced […]

How are mtDNA haplogroups named?

In general, scientists name mitochondrial DNA (mtDNA) haplogroups according to their major branch with a capital letter. They then name subclades (branches) with alternating numbers […]

As a genealogist, do I really need to understand all of this complex information about mitochondrial DNA (mtDNA) in order to use it for my research?

No. As a genealogist, you may focus on a few basic rules. These will allow you to use mtDNA (mitochondrial DNA) to assist with your […]

How many generations back does mitochondrial DNA (mtDNA) testing trace?

Mitochondrial DNA (mtDNA) testing covers both recent and distant generations. Matching on HVR1 means that you have a 50% chance of sharing a common maternal […]

How do I know if I have an mtDNA (mitochondrial DNA) heteroplasmy? What is the nomenclature?

You will know that one of your mutations or differences from the RSRS is a heteroplasmy by its letter codes. Symbol Meaning Symbol Meaning U […]

Are some mitochondrial DNA (mtDNA) mutations more common than others are?

We see some mitochondrial DNA mutations more often than others. One mutation which we find often in a number of different haplogroups is C16311T in […]

What is a mitochondrial DNA (mtDNA) deletion? What is the nomenclature for displaying them?

Deletions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have not been copied. The sequence […]

What is an mtDNA insertion? What is the nomenclature for displaying them?

Insertions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have been added to the DNA […]

What is an mtDNA transversion? What is the nomenclature for displaying them?

Transversions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have changed value. Transversions are where […]

What is an mtDNA transition? What is the nomenclature for displaying them?

Transitions are types of DNA mutations. They are places in your DNA where nucleotides (Cytosine, Guanine, Adenine, and Thymine) have changed value. Transitions are where […]

Where are apostrophes (‘) used in mtDNA haplogroup names?

Apostrophes are used to create a common branch between two well-established branch points in the tree. One example is M1’20’51. It is the common parent […]

Where are zeros (0)s used in mitochondrial haplogroup names?

Zeros are used when a new branch point needs to be inserted above a well-established branch point on the mitochondrial tree. One of the best-known […]

Why do we inherit only our maternal mitochondria?

Male sperm contain paternal mitochondria. After cell fertilization, the paternal mitochondria are eliminated from the newly formed zygote.

Is the mitochondrial DNA (mtDNA) genome completely independent of the nuclear cell genome?

No, it is not. Over time, some of the genetic code from the mitochondrial genome migrates to the nuclear cell genome. However, enough mitochondrial genetic code […]

What are mitochondria?

Mitochondria are specialized subunits (organelle) within cells. In humans, mitochondria are responsible for cell respiration and for producing energy. They evolve into their current state […]

Why do I have a lot of mitochondrial DNA (mtDNA) test matches?

Some mitochondrial DNA (mtDNA) haplotypes show a high number of matches. There are two possible explanations for this. Many people with the same results as […]

Why don’t I have HVR1 and HVR2 (HVR1,HVR2) combined matches?

If you do not have HVR1 matches, you will not have HVR1 and HVR2 (HVR1,HVR2) combined matches. This is because anyone who is an HVR1,HVR2 […]

Why don’t I have HVR1 matches?

You are the first person with your particular HVR1 sequence to be in our database. This can mean that your result is relatively rare and […]

Is my mitochondrial DNA (mtDNA) mutation medical? Is mitochondrial heteroplasmy medical?

Family Tree DNA offers mitochondrial DNA (mtDNA) full sequence tests strictly for genealogy and personal ancestry information. Therefore, we do not examine or discuss medical […]

What is a mitochondrial DNA (mtDNA) heteroplasmy?

Heteroplasmy is the presence of more than one type of a genome (in this context, mitochondrial DNA) within a cell or organism. Put another way, […]

Why are some of my mitochondrial DNA (mtDNA) mutations found on other branches of the tree?

Some mitochondrial DNA (mtDNA) mutations are found throughout the mtDNA tree. This is because the same mutation has happened dozens or hundreds of times in […]

What are mitochondrial DNA (mtDNA) mutations?

Mutations are changes to your DNA code. They are natural copying errors. One analogy is to think of a copy machine that is making many […]

What do my differences from the RSRS (Reconstructed Sapiens Reference Sequence) mean?

When we test mitochondrial DNA (mtDNA), your results are a list of the four bases that make up DNA, represented by the first letter of their name […]

What is the Reconstructed Sapiens Reference Sequence (RSRS)?

The Reconstructed Sapiens Reference Sequence (RSRS) is a mitochondrial DNA (mtDNA) reference sequence that uses both a global sampling of modern human samples and samples […]

What version of the mtDNA Tree Does FamilyTreeDNA use?

We use the V14 version of Phylotree published in Behar et al. 2012, A “copernican” reassessment of the human mitochondrial DNA tree from its root. We […]