Later On

A blog written for those whose interests more or less match mine.

The tangled path DNA testing can take

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Full disclosure: I am awaiting the results of my 23andme test. So I found this lengthy report in the Washington Post of particular interest. Libby Coleman writes:

Five years ago, Alice Collins Plebuch made a decision that would alter her future — or really, her past.

She sent away for a “just-for-fun DNA test.” When the tube arrived, she spit and spit until she filled it up to the line, and then sent it off in the mail. She wanted to know what she was made of.

Plebuch, now 69, already had a rough idea of what she would find. Her parents, both deceased, were Irish American Catholics who raised her and her six siblings with church Sundays and ethnic pride. But Plebuch, who had a long-standing interest in science and DNA, wanted to know more about her dad’s side of the family. The son of Irish immigrants, Jim Collins had been raised in an orphanage from a young age, and his extended family tree was murky.

After a few weeks during which her saliva was analyzed, she got an email in the summer of 2012 with a link to her results. The report was confounding.

About half of Plebuch’s DNA results presented the mixed British Isles bloodline she expected. The other half picked up an unexpected combination of European Jewish, Middle Eastern and Eastern European. Surely someone in the lab had messed up. It was the early days of direct-to-consumer DNA testing, and Ancestry.com’s test was new. She wrote the company a nasty letter informing them they’d made a mistake.

But she talked to her sister, and they agreed she should test again. If the information Plebuch was seeing on her computer screen was correct, it posed a fundamental mystery about her very identity. It meant one of her parents wasn’t who he or she was supposed to be — and, by extension, neither was she.

Eventually, Plebuch would write to Ancestry again. You guys were right, she’d say. I was wrong.

We are only just beginning to grapple with what it means to cheaply and easily uncover our genetic heritage.

Over the past five years, as the price of DNA testing kits has dropped and their quality has improved, the phenomenon of “recreational genomics” has taken off. According to the International Society of Genetic Genealogy, nearly 8 million people worldwide, but mostly in the United States, have tested their DNA through kits, typically costing $99 or less, from such companies as 23andMe, Ancestry.com and Family Tree DNA.

The most popular DNA-deciphering approach, autosomal DNA testing, looks at genetic material inherited from both parents and can be used to connect customers to others in a database who share that material. The results can let you see exactly what stuff you’re made from — as well as offer the opportunity to find previously unknown relatives.

For adoptees, many of whom can’t access information about their birthparents because of closed adoption laws, DNA testing can let them bypass years, even decades, of conventional research to find “DNA cousins” who may very well lead them to their families.

But DNA testing can also yield uncomfortable surprises. Some testers, looking for a little more information about a grandparent’s origins, or to confirm a family legend about Native American heritage, may not be prepared for results that disrupt their sense of identity. Often, that means finding out their dad is not actually their dad, or discovering a relative that they never knew existed — perhaps a baby conceived out of wedlock or given up for adoption.

In 2014, 23andMe estimated that 7,000 users of its service had discovered unexpected paternity or previously-unknown siblings — a relatively small fraction of overall users. The company no longer provides data on surprise results. However, its customer base has more than doubled since 2014, and now contains more than 2 million people — and as more people get involved with recreational genomics, bloodline surprises are certain to become a more common experience. The 2020s may turn out to be the decade that killed family secrets, for better and for worse.

“We see it every day,” says CeCe Moore, a genetic genealogist and consultant for the PBS series “Finding Your Roots.” She runs a 54,000-person Facebook group, DNA Detectives, that helps people unravel their genetic ancestries. “You find out that a lot of things are not as they seem, and a lot of families are much more complex than you assume.”

Alice Plebuch found herself in this place in the summer of 2012. To solve the mystery of her identity, she needed more help than any DNA testing company could offer. After all, genetic testing gives you the what, but not the why.

Plebuch would turn out to be uniquely suited to the role of private eye in her own detective story. Now living in the suburbs of Vancouver, Wash., she worked as an IT manager for the University of California before her retirement. “I did data processing most of my life, and at a fairly sophisticated level,” she says. Computers do not intimidate her, and neither do big questions that require the organization and analysis of complex information. She likes to find patterns hidden in the chaos.

Just the skills necessary to solve a very old puzzle. . .

Continue reading.

It’s long, and there are surprises.

Written by LeisureGuy

27 July 2017 at 11:41 am

Posted in Daily life, Science

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