Participation by one of our project members in the large BeatyByrneMcLaughlin/Leinster cluster has led to the discovery of a SNP mutation which divides the cluster! This SNP mutation, L159, has been found in most of the cluster members in our project that have tested for it, but some cluster members have tested negative. Men who have tested negative tend to share certain similarities with some other men who have tested negative, and we have been able to group the L159- ccgg men whose results are similar to the Leinster modal haplotype into three different groups based on these similarities. Two of these subgroups include men of several different surnames, but their results on standard Y chromosome STR tests including the 37 and 67 marker results show distinctive similarities that make it possible to group them. The other group seems to include one family, the McHale Family. More testing within this family and more testing of men with similar haplotypes would be helpful.

For the most granular results, providing information about branching around and below R-L159, the Big Y-700 test is the best.