Personal genomics and adoption

By Razib Khan | January 23, 2012 9:23 pm

With DNA Testing, Suddenly They Are Family:

Several companies provide tests that can confirm whether adoptees are related to individuals they already know. Others cast a wider net by plugging DNA results into databases that contain tens of thousands of genetic samples, provided mostly by people searching for their ancestral roots. The tests detect genetic markers that reveal whether people share a common ancestor or relative.

Some experts on adoption and genetics have criticized ancestry and genealogy testing companies, saying they are, at times, connecting people whose genetic links are tenuous — in effect stretching the definition of a relative. Nevertheless, the growing popularity of the tests, combined with social media sites that connect people day to day, has given some adoptees a sense of family that feels tangible, intimate and immediate.


I think that these tenuous connections and slivers of information are better than nothing. This isn’t rocket science. And naturally many adopted people also could care less. This is a deeply personal issue, and the valence is going to be private. I suspect that those of us who aren’t adopted, and take for granted knowledge of our own family background have a hard time imagining the value which even a 3rd or 4th cousin could give someone.

Additionally, though finding very close relatives is not that common (first cousins, let alone first order relatives), knowledge of more distant relations can still help you triangulate aspects of family history if you begin with nothing. To give a personal example I know someone whose paternal grandparents were immigrants from Germany. The maternal side is much more mixed, and some of the genealogical records hit dead-ends in the mid 19th century in the USA. It turns out that one of the individuals that this person is closest to on 23andMe is an African American (both maternal and paternal lineages are clearly African). What does this mean? The lead hasn’t been followed up, but combining family histories might be very informative in this case.

CATEGORIZED UNDER: Genetics, Genomics, Personal Genomics
  • pconroy

    In terms of hitting a wall in research, my father-in-law was in that position, he could trace his direct paternal line back to Poland in 1840’s, and then the trail went dead. As a Catholic, he had checked all the Catholic church records and cemeteries in Poznan (aka German Posen), and could find nothing, even though he knew the exact village where his family lived.

    I encouraged him to test with 23andMe, and to his surprise about 1/3 or more of his relatives are Jewish. When he showed me the documents he had, I noticed that the birth name for his GGGrandfather was different from his married name, the birth name was “Berger”, and he said he had always assumed that it was a typo. But now it would seem that his Catholic direct male ancestor had once been Jewish, and like other Jews in Posen, had assimilated and converted in the early 1800’s.

    It so turns out he also has Jewish Italian relatives, and a 1/2 sister of his Sicilian mother – same father, different mothers – also tested and she has none of these Jewish relatives from Italy. So it would seem that his maternal direct line was Sephardic Jewish from Sicily.

  • Naughtius Maximus

    It’s a pity they didn’t mention states like NY not allowing 23andme kits to be mailed there (or at the very least making it very difficult).


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at


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