For genealogical use, tested yDNA markers must be markers that change, but do not change too often. FTDNA uses a mix of fast and slow moving markers in each of their panels, 1-12, 13-25, 26-37 and 38-67. This is useful in helping determine related participants and branches of these families based on the mutations of the fast moving markers.

The five fastest moving Markers are: DYS 464, 449, 439, 385, and 458

DYS 464 is the fastest moving marker and DYS 458 is the slowest in this group of the five fastest moving markers. The other three listed markers fall between the fastest and the slowest of the fast moving markers. There are also other fast moving markers, such as DYS 456, 576, 570 and CDY.

For now we will just address the first 37 markers tested at FTDNA, since the 37 marker test seems to be the test of choice for yDNA testing. When you examine the first three panels, 1-12, 13-25 and 26-37, these are the fast moving markers used in each panel at FTNDA:

First panel, 1 through 12 markers: DYS 385 and 439

Second panel, 13 through 25 markers: DYS 458, 449 and 464

Third panel, 26 through 37 markers: DYS 456, 576, 570 and CDY

As you can see, the markers in the first panel are the most stable and are generally the slowest to mutate, the second panel contains markers that are a little less stable, and the third panel is the most unstable and contains the fastest moving markers. To learn more about the specific mutation rates of each marker above and the more stable markers, this link( will take you to a website that covers this topic.

Fast mutating markers called multi-copy markers.

A few of the fast mutating markers such as DYS 464, 385, and CDY are multi-copy markers. This type of marker is defined by the fact that more than one copy of the marker exists on the Y chromosome. These types of markers bear an additional designation suffix. DYS 464 is broken down into 464a, 464b, 464c and 464d. Some people (less than 5% of the population) also have 464e, 464f and 464g. DYS 385 is known as 385a and 385b just as DYS CDY is known as CDYa and CDYb.

These multi-copy markers are very useful for determining relatedness with a small amount of comparable markers and will also help differentiate branches within a family group of participants as stated above. Results are reported in ascending order for multi-copy markers. It is important to know how to read the results for these multi-copy markers and they can be a confusing, until you know how to compare them. For example let's consider two Prichard men who match perfectly on all but the marker DYS 464.
Suppose these two individuals marker value were this:

Name DYS 464a DYS 464b DYS 464c DYS 464d
John Pritchard 15 15 16 17
Eli Pritchard 13 15 15 17

Upon first appearance, one might think they are two steps away from each other. It is common to line up the results and look at 15 over 13 and 16 over 15 and think there are two mismatches. This is not the case since the markers are read in ascending order. John Prichard has a 15, 15, 16 and 17. Eli has a 13, 15, 15 and 17. They both have 2 values of 15 and 1 value at 17. They match on 3 out of 4 markers within the multi-copy marker of DYS 464. In other words, this mutation only represents a genetic distance of 1, not a genetic distance of 2.

Another example:
Name DYS 464a DYS 464b DYS 464c DYS 464d
John Pritchard 11 11 14 16
Eli Pritchard 12 14 15 16

Here most would think there are 3 mismatches in these results. However, there are only 2 mismatches within these results. John and Eli both have values of 14 and 16; however, John has values of 11 twice and Eli has a 12 and a 15. This represents a genetic distance of 2, not 3.