Chimera Twins Story

skelley writes "Below is an audio link on this morning's story on NPR about Chimera twins, or people with two sets of DNA. It turns out that every once in a while a set of fraternal twin eggs merge into one embryo. The resulting person has two sets of DNA. The story says it is possible for a Chimera to have different sets of DNA in different body parts. This can cause complication for body identification, DNA typing for organ transplants, crime investigation, etc. Researchers have no idea how common this is, but suppose that it is a reasonable percentage of all fraternal twin pregnancies, which would mean millions worldwide. No text version. NPR often doesn't publish one. "

Comments

Re:so the answer is

[CausticWindow]

Using DNA to test for a positive match is a sham. The National Research Council have admitted that much (remember the New York Times controversy when NRC released their report on DNA profiling in investigative work?)

After heavy pressure from various law enforcement agencies, they revised their report to say that it might be appropriate if the labs doing the tests were under strict national quality assurance (which they still aren't).

There have been several cases where a positive DNA match later turned out to indicate nothing more than that a person belonged to a certain group of the population. And there have been convictions that have been revoked because of this.

But imagine what would happen if the NRC published their original report? Thousands of convicts would want their cases retrialed. So that isn't going to happen. And dna profiling continues to be court admissable evidence.

For a good book on the topic, look for "Biologhy as Ideology: The Doctrine Of DNA" by Richard C. Lewontin, professor of biology at Harvard University.

Btw, did you know that the US is one of the few countries in the world where a lie detector test is court admissable?