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Old 17th September 2015, 11:48 PM
dna dna is offline
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Join Date: Aug 2014
Posts: 2,963
Originally Posted by prairielad View Post
STR markers (12 marker level) are used by FTDNA only to Predict haplogroup.
SNP testing by individual is needed to confirm.
If FTDNA can not confidently predict haplogroup based on first 12 markers, they fill run a free SNP test to determine basic haplogroup.
More details can be found in the Family Tree DNA Learning Center How does Y-chromosome DNA (Y-DNA) haplogroup prediction work?

Originally Posted by prairielad View Post
In regards to father son mutation, father and son will always match. Maybe not on the first 12 markers if it is a 1 to 2 step mutation which occurs with one of this levels STR markers, as the 12 marker level only shows exact matches with the exception that matches with a difference of 1 are also shown if the two people belong to the same Group project.
It was reported in the forum that father and son can differ in up to 3 markers. I would not try to limit those differences to any particular markers. Thus they are guaranteed to be matches in Y-DNA67 and Y-DNA111 results, as presented by FTDNA. However, matching at Y-DNA12, Y-DNA25 and Y-DNA37 might or might not happen. Most of father and son pairs match at all levels (regardless of Genetic Distance), however there is no guarantee of that.

Mr. W
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