Possibly Puerto Rico is one of those areas that is a "geography" rather than a "geneology"... like the U.S. For example the United States doesn't show up in DNA - because we are all for somewhere else. I was looking for Mexico or hispanic in my DNA... and people explained that not going to see "Mexico"... I'll see the geneology from the peoples who migrated to Mexico rather than the native Indian tribes. Mine said British Isles, Scandanavian, and EAstern Europe. So those peoples probably are the ones who migrated to Mexico in my case. In your case - the Puerto Rico could be most definitely be former african slaves who migrated away from the south U.S. as well as europeans. Does that help? Definitely do your son to see the results. I was also told that DNA jumps around. Like my brother and I won't have the same percentages - I depends on what I was given in the big DNA soup that makes up us.