Which Y-DNA STR markers do FamilyTreeDNA test?

At FamilyTreeDNA, we test 561 Y-chromosome DNA short tandem repeat (STR) markers in our standard Y-STR tests: Y-DNA12, Y-DNA25, Y-DNA37, Y-DNA67, Y-DNA111, and Big Y. […]

What is different about the STR markers DYS389I and DYS389II? Why is my DYS389II (DYS389-2) result at FamilyTreeDNA different from the Genographic Project?

The Y-chromosome DNA (Y-DNA) marker DYS389 is a single STR marker that has four parts: m, n, p, and q. At FamilyTreeDNA, we have two tests […]

Do more Y-DNA STR markers improve the quality of matches’ information?

You should test more Y-chromosome DNA short tandem repeat (STR) markers when you wish to compare additional markers against others with similar results. They will […]

Don’t we all go back to Africa?

Yes. All of our Y-chromosome lineages trace back to a common ancestor who lived in Africa at least 115,000 years ago. Some lineages migrated out of […]

How does the infinite allele comparison method work for palindromic markers?

For palindromic markers, the infinite allele method counts a difference for two types of changes: a mismatch and a copy number change. Mismatches occur when the […]

How many generations does a Y-chromosome DNA (Y-DNA) STR test trace?

Y-chromosome DNA (Y-DNA) tests trace both recent and distant generations. The number of generations traced by a Y-chromosome DNA test depends on the type of […]

Why do I have more than one result for an STR value? What is a multi-copy STR marker?

A multi-copy STR marker is one where there are multiple versions of the same STR in different locations on the Y-chromosome. Each STR copy changes […]

What is the likelihood of a non-paternal event or false paternity?

We believe that the rate of unannounced adoption or false paternity is about 1 – 3% per generation and compounds each generation. When confirming your […]

What does each short tandem repeat (STR) marker mean?

By themselves, Y-chromosome DNA (Y-DNA) short tandem repeat (STR) markers from a Y-DNA test do not have any particular meaning. The value of testing Y-DNA […]

Why don’t my Y-chromosome DNA (Y-DNA) test results show me percentages?

Your Y-chromosome DNA (Y-DNA) test results cannot be used to indicate your percentage of DNA from different ancestral groups. This is because tracing your Y-DNA […]

If somebody doesn’t match me at 12 markers, how can they match me at a higher testing level?

Aside from their having matching turned off at the Y-DNA12 level, someone might match you at a higher testing level but not Y-DNA12 because the […]

If two men share a surname, how should the genetic distance at 111 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname […]

If two men share a surname, how should the genetic distance at 67 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname […]

If two men share a surname, how should the genetic distance at 37 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname […]

If two men share a surname, how should the genetic distance at 25 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname […]

If two men share a surname, how should the genetic distance at 12 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname […]

Expected Relationships with Y-DNA STR Matches

The expected relationship between you and your Y-chromosome DNA (Y-DNA) match is dependent on both the number of markers you have tested and the genetic […]

Y-DNA Genetic Distance

When talking about two or more Y-chromosome STR (short tandem repeat) haplotypes, genetic distance is the total number of differences or mutations between two sets […]

Y-DNA Step Mutations

When comparing the results of Y-chromosome STR (short tandem repeat) tests, the difference between the two values at a marker is the Y-DNA genetic distance […]

What does the WAMH badge on my personal page mean?

The Western Atlantic Modal Haplotype Match badge on the My Account – Personal Profile page of your myFTDNA account means that you match or are close […]

What does the Niall of the Nine Hostages badge on my personal page mean?

The Niall of the Nine Hostages Match badge on the My Account – Personal Profile page of your myFTDNA account means that you match exactly or […]