6 percent of my ancestry that is Italian disappears

canada goose clearance sale Ancestry DNA Tests Don’t Always Find What We Expect canada goose clearance sale

canadian goose jacket Maybe you got one of those find your ancestry kits over the holidays. You’ve sent off your awkwardly collected saliva sample, and you’re awaiting your results. If your experience is anything like that of me and my mom, you may find surprises not the dramatic “switched at birth” kind, but results that are really different from what canada goose outlet miami you expected. canadian goose jacket

Canada Goose Jackets My mom, Carmen Grayson, taught history for 45 years, high school and college, retiring from Hampton University in the late 1990s. But retired history professors never really retire, so she has been researching her family’s migrations, through both paper records and now a DNA test. Her canada goose outlet vancouver father was French Canadian, and her mother (my namesake, Gisella D’Appollonia) was born of Italian parents. They moved to Canada about a decade before my grandmother was born in 1909. Canada Goose Jackets

canada goose clearance Last fall, we sent away to get our DNA tested by Helix, the company that works with National Geographic. Mom’s results: 31 percent from Italy and Southern Europe. That made sense because of her Italian mother. But my Helix results didn’t even have an “Italy and Southern European” category. How could I have 50 percent of Mom’s DNA and not have any Italian? We do look alike, and she says there canada goose outlet store uk is little chance we were switched at birth. canada goose clearance

canada goose deals We decided to get a second opinion and sent away to another company, 23andMe. We opened our results together and were just as surprised. This time, I at least had a category for southern Europe. But Mom came back as 25 percent southern European, me only 6 percent. And the Italian? Mom had 11.3 percent to my 1.6. So maybe the first test wasn’t wrong. But how could I have an Italian grandmother and almost no Italian genes? canada goose deals

Canada Goose online To answer this question, Mom and I drove up to Baltimore to visit Dr. Aravinda Chakravarti of the Johns Hopkins University School of Medicine and the Bloomberg School of Public Health and who has spent his career studying genetics and human health. Canada Goose online

“That’s surprising,” he told us when we showed him the results. “But it may still be in the limits of error that these methods have.”

canada goose coats on sale The canada goose outlet locations in toronto science for analyzing one’s genome is good, Chakravarti says. But the ways the companies analyze the genes leave lots of room for interpretation. So, he says, these canada goose jacket outlet sale tests “would be most accurate at the level of continental origins, http://www.mycanadagoosejacket.org and as you go to higher and higher resolution, they would become less and less accurate.” canada goose coats on sale

buy canada goose jacket cheap As in my case the results got me to Europe, just not Italy. buy canada goose jacket cheap

Canada Goose sale My 23andMe test also showed less than 1 percent of South Asian, Sub Saharan African, and East Asian Native American. This, Chakravarti says, is likely true because the genetics of people on a continental level are so different, and it’s not likely canada goose jacket outlet toronto South Asian is going to look like European. “Resolving a difference between, say, an African genome canada goose outlet washington dc and an East Asian genome would be easy,” he says. “But resolving that same difference between one part of East Asia and another part of East Asia is much more difficult.” Canada Goose sale

I also learned that even though I got half my genes from Mom, they may not mirror hers.

We do have the genes we inherit 50 percent from each parent. But Elissa Levin, a genetic counselor and the director canada goose outlet trillium parka black of policy and clinical affairs of canada goose outlet online uk Helix, says a process called recombination means that each egg and each sperm carries a different mix of a parent’s genes.

buy canada goose jacket “When we talk about the 50 percent that gets inherited from Mom, there’s a chance that you have a recombination that just gave you more of the northwest European part than the Italian part of your Mom’s canada goose outlet black friday sale ancestry DNA,” canada goose outlet boston she says. That is also why siblings can have different ancestry results. buy canada goose jacket

The companies compare customers’ DNA samples to samples they have from people around the world who have lived in a certain area for generations. The samples come from some databases to which all scientists have access, and the companies may also collect their own.

canada goose store “We’re able to look at, what are the specific markers, what are the specific segments of DNA that we’re looking at that help us to identify, ‘Those people are from this part of northern canada goose factory outlet toronto location Europe or southern Europe canada goose outlet michigan or Southeast Asia,’ ” Levin says. canada goose store

canada goose black friday sale As the companies collect more samples, their understanding of markers of people of a particular heritage should become more precise. But for now, the canada goose jacket outlet uk smaller the percentage of a population canada goose outlet within a continent that is in the database, the less certain they are. Levin says Helix chooses to not report some of those smaller percentages. canada goose black friday sale

The 23andMe canada goose outlet nyc reports results with a 50 canada goose outlet usa percent confidence interval they’re 50 percent sure their geographic placement is correct. Move the setting up to 90 percent confidence, meaning your placement in a region is 90 canada goose outlet store toronto percent certain, and that small 1.6 percent of my ancestry that is Italian disappears.

The ancestry tests also have to take into account the fact canada goose outlet store quebec that humans have been migrating for millennia, mixing DNA along the way. To contend with that, the companies’ analyses involve some “random chance” as Levin puts it. A computer has to make a decision.

cheap Canada Goose And the ancestry canada goose outlet black friday companies have to make judgment calls. Robin Smith, a senior canada goose outlet toronto address product manager with 23andMe, says their computers compare the DNA with 31 groups. “Let’s say a piece of your DNA canada goose outlet edmonton looks most like British and Irish but it also looks a canada goose outlet los angeles little bit like French German,” he says. “Based on some statistical measures, we’d decide whether to call that as British Irish or French German, or maybe we go up one level and call it northwestern European.” cheap Canada Goose

canada goose coats What does he think explains my case? canada goose coats

Canada Goose Outlet “It was a bit surprising,” he says. “But in looking at the fact that you have some southern European and some French German, the picture became a little clearer to me.” Canada Goose Outlet

So, for now, my Italian grandmother doesn’t show up in these tests. No matter Chakravarti, Levin and Smith all say let the results add to your life story. The DNA is just a piece of what makes you you.

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