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Identical Twins Test 5 DNA Ancestry Kits, Get Different Results On Each (www.cbc.ca)
Freshly Exhumed writes: Uh-oh, something is not right with the results of most popular DNA ancestry kits, as a pair of identical twins have found. Charlsie Agro and her twin sister, Carly, bought home kits from AncestryDNA, MyHeritage, 23andMe, FamilyTreeDNA and Living DNA, and mailed samples of their DNA to each company for analysis. Despite having virtually identical DNA, the twins did not receive matching results from any of the companies. "The fact that they present different results for you and your sister, I find very mystifying," said Dr. Mark Gerstein, a computational biologist at Yale University. Gerstein's team analyzed the results, and he asserts that any results the Agro twins received from the same DNA testing company should have been identical. The raw data collected from both sisters' DNA is nearly exactly the same. "It's shockingly similar," he said.
Some people don't realize that none of these services sequence the full genome. They sequence a collection of different sites as best they can (from the spit that you send them in a tube). Some sites will be sequenced really well and some not at all; it is the random nature of the system. What happens if twin 1 is sequenced really well at site ABC123 and has some rare mutation there but twin 2 is not sequenced at that site at all? They will assume that twin does not have the mutation - they will sub in "wild type" sequence at that locus as they won't have any thing better to go on - and you'll end up identifying them as being different. Take this many times over thousands of gene loci that they sequence and pretty soon you see how two identical twins can end up looking very different.
If you want to see how similar they really are at the DNA level, you need Whole Genome Sequencing (WGS) or at least you need to know what the coverage was at each locus for each twin. The former still costs thousands in most cases, the latter should be in the raw data (though they would need to convince the companies to release said raw data to them).
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
These are not the same things.
The story was discussing the labs' reporting of ethnic heritage, not matching two DNA samples against each other to find out if they are the same person's DNA.
The story itself noted that the RAW DATA was nearly identical, as one would expect with identical twins. It was only the calculation of ethnic background that is (somewhat) in doubt.
The raw results are not in question. The story itself says that the raw data was nearly identical, as one would expect. It is only the extrapolation of that data to infer ethic lineage that didn't line up so well.