Preimplantation Genetic Haplotyping

There has been alot of great analysis of the recent announcement that a couple in England has used the new technique of preimplantation genetic haplotyping (PGH) to have twins that did not have cystic fibrosis.

Preimplantation genetic haplotyping is a twist on preimplantation genetic diagnosis (PGD).  In PGH a normally fertile couple, who wants to have a disease-free child, undergoes IVF.  The resulting embryos have a single cell removed and that cell is tested for mutations that cause disease.  PGH differs from PGD in that is uses DNA fingerprinting to determine which embryos are healthy.  DNA fingerprinting is kind of like a DNA barcode unique to each individual.  DNA fingerprinting is the technique used in forensic laboratories to identify possible suspects in a crime.  With DNA fingerprinting, PGH can screen for many more diseases than traditional PGD, around 6,000.  The "healthy" embryos are implanted and the "unhealthy" embryos are most likely discarded or donated to research.

The Catholic Church finds both PGH and PGD immoral.  Not only is it against the dignity of every human being to be produced in a petri dish, but to discard a new human life because of a genetic defect is, to put it mildly, a big no-no.

But PGH sure does tug at the heart strings.  The couple in question, the Greenstreeets used PGH to have twins free from CF after they had a daughter with the disease.  From the Daily Mail:

Today, Mrs Greenstreet, 38, defended her decision to reject the imperfect embryos, saying she and husband Jim, 41, did not want to repeat the experience of caring for a seriously ill child.

"Unless you have lived with a child that has a terrible disability or disease then you can't speak about it," she said.

"Who can criticise you for trying to get rid of horrible diseases? Why would you want to see people suffer? When you have got these lovely healthy babies in your arms it dampens all the pain we went through. They are designer babies but they are designed for the good of mankind."

Now that is a heart-wrenching statement.  Cystic fibrosis is a devastating disease and currently incurable.  But, I believe there is hope in things like gene therapy.  I whole-heartedly sympathize with this family, and I pray that God gives them all comfort and solace.  Those twins are a blessing, as all children are.  That does not mean that this was morally right.

Here is why.  Look into that little girl's face.  She is adorable.  She is also "genetically defective."  By discarding embryos with her same defect, her parents are saying that if they had known, she would have never been born.  How does her parents actions affect her?

And therein lies the rub.  I test for CF mutations everyday.  I test many pregnant women for CF carrier status. The idea is that if mom is a carrier and dad is a carrier, then an amniocentesis is performed to see if the fetus has CF. Of course, abortion is always an option.

I was surprised to learn that some in the CF advocacy community are against carrier screening and testing fetuses for CF. Why? Because it focuses on getting rid of the genes, not curing the disease.

And the reality is that even if PGH and eugenic abortion were widespread,  CF is not going away.  There are over 1000 documented mutations, and counting, that cause CF.  Most labs only test for around 70.  Which means there will still be children born with CF.  What happens to those children if most of those like them are not allowed to live?

With every eugenic abortion and PGH screen, not only does their funding and their hopes for finding a cure diminish, but the likelyhood of their having to justify their existence increases. Sound extreme? Maybe. But there was a recent case of a woman who was told by her insurance company, “Abort your baby that has CF or we won’t pay for any treatments.”

PGH is the very situtation for which the cliche "throwing the baby out with the bathwater" was coined.  Especially when you consider that there are some people walking around with two CF mutations, and therefore should have the disease, yet do not know it.  I know.  I have tested such a woman.

The focus needs to be on curing the disease, not making sure that no more children with CF mutations are born.  The later focus has devastating consequences for parents and children alike.  I can't say it better that Elizabeth R. Schiltz, an Associate Professor of Law at the University of St. Thomas School of Law in Minneapolis, Minnesota:

From time to time, we are all confronted with the disconnect between how we see ourselves and how others see us. I've always seen myself as a responsible, law-abiding citizen. I recycle, I vote, I don't drive a Hummer. But I've come to realize that many in the scientific and medical community view me as grossly irresponsible. Indeed, in the words of Bob Edwards, the scientist who facilitated the birth of England's first test-tube baby, I am a "sinner." A recent book even branded me a "genetic outlaw." My transgression? I am one of the dwindling number of women who receive a prenatal diagnosis of Down syndrome and choose not to terminate our pregnancies.

So when I hear about medical breakthroughs like preimplantation genetic haplotyping (PGH)—a new technique to screen embryos in the in vitro fertilization process for 6,000 inherited diseases—I can't help but see 6,000 new reasons that parents will be branded as sinners or made to feel socially irresponsible for bringing their children into this world.