Science news — more problems with DNA chimeras

Just a fascinating story here. Imagine that a woman has chimeric egg cells and because of that, she's accused of faking a pregnancy to defraud a state welfare system. I have written before about chimeras, but had never before thought about chimeric egg cells. Per the story, the phenomenon, germ-line chimerism, is little known, and can hit sperm cells as well.

Here's one such story: 

One such case involved an American man who learned through a paternity test that he could not be the father of his child, who was conceived via assisted reproduction. He was preparing to sue the clinic, believing himself to be the victim of a semen mix-up, when a more precise test revealed that he in fact shared 25% of his DNA with the child. In other words, he was the child's uncle, genetically speaking. Further research showed that 10% of his sperm contained DNA from a vanished twin brother.

There's a religious side note, too. This gives a further swift kick to Catholic doctrine of ensoulment. 

Per the link, there's a new book out about this, and this piece excerpts from that book.

Beyond people allegedly trying to rip off the government, false DNA reports obviously affect criminal justice. Note that chimeras can result from an absorbed embryo of a "fraternal" twin as well as an identical one. So, DNA from a chimera might match a brother or sister more than the person who should be and might be the top suspect.

Here's that, from the book:

The oft-taught equation of "one individual, one genome" fails to capture the full complexity of reality. What seemed a long-established and unshakable certainty, even to me, has turned out to be imperfect knowledge in need of revision. We know too little about our own biology to have blind faith that DNA profiling will always reveal a person's identity or origins. 

Our ultimate proof is far from foolproof. Yet it is very often used to determine relationships, prove or disprove paternity, evaluate applications for family reunification, or convict persons otherwise presumed innocent.

Per the story, as with the woman at top? You might face fraud charges, as well as a criminal defense problem. You might face medical health problems that can't readily be identified, such as people discovered to be chimeras when needing a transplant. Then there's blood typing and other issues. 

On the science, we know that fetuses can make their mothers into chimeras.  

The author, Lisa Barnéoud, notes it's little known how many cases of chimerism exist in general. At least a dozen of specific germ-line cases are known. As I noted years ago about a Carl Zimmer piece, human chimeras, or chimeras plus the somewhat similar phenomenon of "mosaics," probably make up a lot bigger percentage of the population than most people think.

On the metaphysical and religious issues, as I have said before, this just gives a swift kick in the nads to "intelligent designer" claims. 

These two issues are also a challenge to the classical "dual-omni" god and starkly raise the problem of evil, as well as challenging Catholic (and other) ensoulment at birth ideas.