Jones comes to the doctor and says, “Doc, I’m suffering from cancer.” Doc says, “No problem. Got the cure right here.” Doc pulls out a gun and shoots Jones in the cranium. Doc buzzes the intercom and says, “Nurse, send in Smith.” Smith comes in and Doc says, “You’re now Jones, and you’re cured.”

This make sense?

It ought to. Because this joke relies on the same logic touted by those who have created the first “three-parent” baby. These (mad?) scientists say, in effect, that by “discarding” one sick baby and replacing it with another healthy baby, they have “cured” the first. Or they say that by preventing the birth of a potentially sick first baby, and allowing the birth of a potentially healthy second baby, they have “treated” the first.

Make sense yet? No? Then we need to understand what a “three-parent” baby is.

Making Babies

The traditional scientific formula for making a baby is one dad plus one mom, or one sperm plus one egg. After insemination, two “protonuclei” form inside the mother’s egg. One of these blobs contains the father’s DNA, and one the mother’s. Swimming around these protonuclei is the mother’s mitochondrial DNA (mDNA). A short time after, the protonuclei and mDNA mix, the egg begins to cleave and away we go. The cells split and differentiate and, if all goes well, they emerge into the world, live three score and ten or so, then die. (Birth is an intermediate step after conception in this “process”.)

Under the Mary-Shellyesque technique called pronuclear transfer, two separate babies are created using two different sperm (from the same father) and two different eggs (from two women). The female protonuclei from both eggs are removed. The donor’s female protonucleus is ash-canned but her egg is kept, into which is inserted the mother’s female protonucleus. What remains in the donor’s egg is her mDNA. Hence one life is killed (at least one, since the procedure is imperfect), and a new one created with DNA from one father and two women.

A second way of doing this, and the one making headlines, is maternal spindal transfer. Before any egg is inseminated, the nuclear DNA, but not the mDNA, from a mother’s and a donor’s eggs are removed, and the mother’s nuclear DNA is inserted into the donor’s egg, which retains the donor’s mDNA. This hybrid egg is then artificially inseminated with the father’s sperm. If the resultant embryo lives, it’s inserted into the mother and the birth progresses as usual.

There are other formulations, but all end in the same position: a fertilized egg with the father’s DNA, the mother’s nuclear DNA, and a donor’s mDNA. A “three-parent” baby. Of course, the processes described are not as “clean” as they appear: errors in holding back or transferring mDNA happen.

Since all this is iffy technology, the inseminations don’t always work. In the case of this new child, according to New Scientist five separate embryos (lives) were created, “only one of which developed normally. This embryo was implanted in the mother and the child was born nine months later.” The others died. Not a good ratio, that.

When a “Cure” is Not a Cure

Why do this at all? Because there are some heritable diseases associated with mDNA. In this case, the mother had Leigh syndrome, “a fatal disorder that affects the developing nervous system” and which could be transmitted in her mDNA. Indeed, the mother has already had two children who had subsequently died from this disease. The parents wanted a child not susceptible to this syndrome, and so turned to these new technologies.

The doctor who led the team, John Zhang, of the New Hope Fertility Clinic in New York, did the procedure in Mexico where, he said, “there are no rules.” This lack of rules brings us back to the bitter joke we started with. In justifying his procedure, Zhang said, “To save lives is the ethical thing to do.” Yet Smith replaces Jones: Smith is not Jones cured.

No lives were saved by Zhang. No lives will be saved. No lives can be saved.

What happens is that some lives are prevented, while some are ended to facilitate the birth of others. No diseases are “cured.” A cure is when a person with a disease has that disease removed. In “three-parent” child-making, a person who might get a disease is either prevented from being conceived, or conceived then killed.

The hubris of Zhang and others astonishes. Any language of “curing” or “treating” diseases or of “saving” lives here is nothing but propaganda. What these scientists are doing is pure genetic engineering with the goal of creating supposedly superior beings. They are superior in the sense that they are less likely to contract certain diseases compared with others who would be born in their place. Genetic engineering won’t stop at health. There are already discussions of designing “super-intelligent” people, or giving children a strong “predisposition to musicality“, or producing other traits chosen by fashionable parents.

The Curse of Over-Certainty

As we ponder the obvious legal and ethical difficulties of having three “parents,” which are too large to go into here, we should be appalled by these scientists’ callousness. In their eagerness to make headlines and break taboos, they never stopped to think of these children’s welfare, or that of their potential descendants.

What is the precise, biological interaction between a mother’s mDNA and her nuclear DNA? What will happen to children with engineered genes at adolescence? When they wish to have children themselves? How exactly will these hideously complex biochemical and genetic interactions play out? Answer: nobody knows. What “side effects” are thus likely to occur in “three-parent” children? Answer: nobody knows.

Is human life so predictable that we can at conception unambiguously forecast the livelihoods of these engineered children? Once it gets out, and it will, that a person has been genetically engineered, how will others view him? Answer: nobody knows.

There are only guesses, ignorance, wild hope, and a brazen willingness to experiment on real people as if they were lab rats. This isn’t playing God. God loves people. This is playing Dr. Frankenstein.