Haplogroup O-CTS3663 is a Y-chromosome (paternal) haplogroup on TheYtree, catalogued with its defining mutations, sample distribution and phylogenetic tree.
| ISOGG name | O2a1b1a1a1a1a1a |
|---|---|
| Defining mutations | 3 |
| Downstream branches | 524 |
| Estimated age | 8,100 years |