Is there a particular significance to

[Joel Hill]

Being a perfect match with someone other than being off by 1 with DYS442 being the difference??

Thanks

[Jim Barrett]

How many markers did each of the two people test for?

[Joel Hill]

I tested

At 37 and 67....

[spruithean]

I don't think a mismatch at DYS442 is super significant, unless there is new information on the mutation rates of DYS442.

[John McCoy]

Even if there were new information about the mutation rate of one STR, unless the mutation rate were incredibly high (in which case this STR would have been too unstable to be selected for use in the Y STR panels in the first place), the significance is still the same: One sample is different from another, by one step, as a result of a random mutational process of some kind. Mutation rates tell you about probabilities and averages, but they don't tell you precisely at which generation a mutation occurred (unless you happen to have other evidence). A genetic distance of 1 between two samples from a Y-67 test strongly suggests, but does not prove, a genealogical relationship within a genealogically significant time frame. The "TiP" report will suggest a range of generations.