Re:GlaxoSmithKline makes $300M investment in 23andMe, forms ...
by ig1 on Thursday July 26, 2018 @07:27AM
(#17616568)
Those aren't false positives in that they represent real genetic relationships (i.e they're identical by descent), as the database size increases you don't increase the false positive rate in any meaningful sense at higher match levels.
If you've got a identical twin then you're right that their child will be genetically indistinguishable from your child. But that's down to the nature of genetics rather than anything to do with the reliability of testing or database size.
Re:GlaxoSmithKline makes $300M investment in 23andMe, forms ...
by Retric on Thursday July 26, 2018 @09:53AM
(#17617491)
False positives don't necessarily mean the test was executed incorrectly. It often means you are testing for something closely related to the information you want.
If a test failed because _ then it failed independent of why it failed. If your long lost twin causes you to be involved with a paternity suit or homicide investigation then that's both a false positive and a significant problem.
Paternity tests involve random ~50% of your dna. Sperm samples are generally contaminated and thus less clear cut. But, people’s relatives have been used in the past for these tests dropping the bar even further.
However, being related genetically is not enough. Some people have twin siblings they don’t know about pointing out being related is not nessisarily mean you know anything about the other person allowing for false positives even at 3,400cM.
Unlikely sure, but harm comes in many forms. Saying I can’t think of anything is a long way from saying it’s safe.