"High ROH" in your DNA - what is it and what can you do next?

Sometimes in the course of testing DNA, we get a surprise with the results. A surprise we have found happening more often the more we test is the DNA feature of high levels of ROH, or "runs of homozygosity." This feature often reveals a recent close genetic relationship between the parents of the person tested. 

If you have used a tool to analyze your DNA like the "Are Your Parents Related?" tool on GEDmatch (or David Pike's tools), and the results show the probability of your parents being closely related is high, the "High ROH" information sheet is for you. Click the link below to see it. 

Sometimes only a small region of DNA (or only one chromosome) shows a high ROH result. Different biological reasons explain these findings. Reach out to Watershed DNA if you need more support.

If you could use support in the form of the story of someone else who discovered ROH, you can follow this link to John’s story about his ROH discovery here.

**This post was updated 12/29/18 to include the link to the updated version of John’s story and shared with his permission.