This is a R1b-U106* subgroup project. Participants should have tested positive for R1b1a2 and exhibit a specific recombination event (RecLOH) that show twin alleles at all of the following three markers; DYS459, DYS464 and DYS724 (CDY). A high proportion of DYS459 are 9-9, DYS464 are 15-15-17-17, 16-16-17-17, or 17-17-17-17, and CDY are 34-34, 35-35, 36-36, 37-37, 38-38, or 39-39 combinations with DYS435 = 10.