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Can ethnicity help with unknown parentage?

Recently ethnicity was a major factor in figuring out the family of the mystery father of an Australian women of mixed heritage: Chinese, Italian, and English/Irish. We still need some help, so any Australian readers please read to the end.

Elana’s ethnicty on Ancestry after the update, before she had lots more Italian

This case is unusual because for those of us with primarily European ancestry, the ethnicity predictions from the various DNA test companies are not accurate enough to be a significant aid with figuring out unknown parentage situations. For one thing, our ancestors moved around more than you might expect, and for another, the science is just not exact enough yet.

Too often I get a panicked email or comment from someone who is worried that Daddy is not their dad, or perhaps grandad is not, because their ethnicity predictions show no German or French or Bulgarian which he was and where is that Norwegian from? To which I respond, check your matches, if you have matches to cousins from his family, all is well, it’s just the inaccuracy of ethnicity predictions. North Europeans and South Europeans are fairly distinct from each other, but countries as we know them today did not exist in the far past.

Comparing ethnicities for Elana (left) and her mother (right) at Ancestry

In Elana’s case, having East Asian and Southern European in addition to the usual Australian British mix, actually gave us some different and potentially useful data to work with. Her mother seemed entirely English, Welsh, Scottish and Irish, a frequent blend for an Australian. She remembers that Elana’s father said he was part Maori and that his name was Bob. There is no Maori in her results shown above (it usually looks Polynesian), so likely he was just trying to make himself seem exotic and interesting.

Elana’s best matches at ancestry were almost all maternal (yes this is a squashed image)

Since Elana’s mother tested also, we could see that Elana had no close matches that were not listed as “Mother’s side” on Ancestry which made the search very difficult. Her paternal matches consisted of only one 3rd cousin, an American of Italian ancestry, and lots of 4th cousins, quite a few with trees, and most of the closer ones were of Italian descent, in spite of only 7% Italian listed in her Ancestry ethnicity.

One possibility for so few paternal matches was related parents. We checked that by uploading to GEDmatch.com (click here for my post on related parents) and that was not the case. The other more likely explanation was very few of her father’s relatives had tested. For example, Elana had only one very distant Asian match in spite of her father clearly having half that heritage.

Since we could see both Elana’s ethnicity and her mother’s it was easy to tell that Elana’s unknown father was half Chinese/Korean with an Italian (great) grandparent. These were her initial percentages before the recent update at Ancestry:

65% England/Scotland/Wales (so her father will have about 15%)
16% Korea and Northern China
12% China
7% Italy

I asked Elana to also test at 23andme and to upload her Ancestry results to MyHeritage and Family Tree DNA as well. Still no luck finding close paternal matches.

 

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Going Gluten Free: What Does Your DNA Say?

Celiac disease (CD) is an autoimmune system response to gluten which can damage the small intestine. Gluten is a protein found in wheat, barley, and rye. Added gluten is often used by commercial bakers to make breads rise faster.

So why are so many people claiming major benefits from going gluten free? I am usually dubious of the latest diet craze but …

I discovered that my usual morning congestion vanished after the first two weeks of a weight loss diet which had eliminated bread. It occurred to me that I had inadvertently been gluten free. So I asked a cousin who had given up gluten about her experience and she explained that her perpetual debilitating sinus infections were gone now. Still dubious, I added bread slowly back into my diet. One ear infection and much congestion later, I started to think that gluten might actually be a problem for me.

I wondered if there was anything reported on this in my DNA. I opened my latest 23andme Genetic Health Risk report (under the top menu item Health)


(red arrow added by me) and saw that I have an increased risk for celiac disease:

When I clicked the Slightly increased risk to get the report I saw this:

It is important to understand that having a genetic variant associated with a disease does not mean you will get it, just that you are more at risk. There are usually many other factors that are needed to cause the condition. Science is still at the very early stages of figuring out the roles our genes play in various diseases.

My initial research suggests that people with celiac disease (CD) just about always have one or both of these variants, however having them does not guarantee that you will have gluten issues.

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