What is the biggest reason paternity tests are wrong?
You were thinking about getting a paternity test, but you're worried that it's going to be wrong. You've heard people talk about this happening in the past.
Some of the reasons seem a bit far-fetched, though. For example, you've heard of chimeras. These are people who originally would have been just one half of a pair of fraternal twins, but the cells combined in the womb into a single individual. Or you've heard about people who had two partners who they didn't realize were related, making it hard to match the DNA to the father and the child.
These things can happen and they have in the past. However, the biggest reason that a test will be wrong is simple: human error. Someone makes a mistake and you get an inaccurate result.
For instance, you could send the DNA samples to the lab. The tech who is doing the job could mix them up. It could be a simple communication error, or perhaps someone else just put the wrong labels on the samples. Two samples get switched, and both people get the wrong results.
Errors are also made when techs aren't careful while doing the test. If the sample is contaminated after it's sent out, the results may be wrong. There's nothing you can do, and the lab workers may not realize the contamination has occurred.
On the whole, DNA tests are very accurate. It is possible for them to be wrong, but they're far better than older types of tests. If you're getting one for the first time or considering another one after what you believe are inaccurate results, they can help establish your legal rights moving forward.
Source: The Tech, "Genetic Testing," Dr. Barry Starr, accessed Oct. 04, 2017