We have mentioned eugenics in several recent posts (e.g., here and here), but it's a thorny subject worth pursuing more fully. Indeed, 'Deadly Medicine', an exhibit from the US Holocaust Museum, is at Penn State for the next few months, reminding us that eugenics was alive and well in the US before the Nazis put it into practice.
There are two faces of eugenics. One is the goal that parents have of not bearing undesirable children. Normally, that means children with serious disabling disease. It can be a noble wish and even a noble act. So long as abortion or in vitro fertilization (IVF) and embryo screening are considered morally acceptable options, and the suffering of the embryo or fetus is not considered to be great, genetic screening can achieve this end. Premarital screening also works, if couples can be dissuaded from marriage (or from child-bearing) if they could produce such offspring (and, indeed, an AP story reporting that many genetic diseases are in decline because of prenatal testing was widely published on Feb 17).
If two carriers of recessive alleles (genetic variants) that are potentially harmful have children, then 1/4 of their offspring would inherit the 'bad' allele from each parent and would be affected with the disease. Call the defective allele 'd' and the normal one 'D'. Each parent is a Dd genotype. Randomly picking one of the alleles from each parent gives a 1/2 chance of picking d from each, or 1/4 chance of picking d's from both. These are the classical proportions discovered by Mendel.
There are many single-gene diseases for which, if the 'd' alleles are known, parents can be screened to determine if they are at risk of producing a dd offspring. Not implanting such an embryo, or aborting such a fetus, prevents the birth of someone carrying the disease.
Tay-Sachs disease in the Jewish population, and serious anemias called Thalassemia, are examples of diseases that have actually been substantially reduced or even nearly eliminated by such screening programs.
The fact is that, like much else in life, the genes have many--often hundreds--of alleles, and only a few of them are known to be seriously harmful. Others confer lesser risk and for most of them we simply don't know. It's less clear about alleles whose effects are uncertain, with comparably complicated moral issues associated with aborting these if they're detected. Still, even those few that are known are clear.
Most of us these days would consider this not just acceptable but a good form of personal eugenics. Others, however, object morally to any abortion, to making God's decisions, or to labeling disabled people as somehow not fully human or not worth living. A whole field of 'disability studies' deals with these issues, and much is being written about the degree to which meaningful, valuable lives can be lived by those formerly considered unworthy--hence questioning blanket policies of aborting them. These are ways in which the morality of eugenics enters society.
Is there a place to draw the line as to what counts as disease? If we ever learn to evaluate a fetus's IQ from its genotype, would it be OK to abort 'stupid' fetuses? If so, should parents be allowed to determine the decision point on the IQ scale? What about, say, musical or athletic ability? What about engineering genes into an embryo to give it traits you want your children to have?
Most if not all the humans who have had their whole genomes sequenced have genotypes at some genes that are 'disease' genotypes. The discoverer of DNA structure, Jim Watson, is one. As someone has quipped, if his own technology had been available to his parents, in the current climate of personal eugenics, he would have been aborted!
What about sex? In some countries there is reportedly substantial prenatal testing and aborting of female fetuses, because sons are more valuable to the parents than daughters. Is that OK? As long as the parents, and not society, make the decision? Of course, this can have ramifications into succeeding generations, as males find it difficult to marry, creating a sort of pendulum effect as to which sex is more valued.
The fears of eugenics imposed by society, as was done in the first half of the 20th century, spook many people as we increasingly enter the genetic age in which the belief is strong that genes generally will predict one's traits, one's identity as a person. We might not impose gas chambers on people because of their group membership, but what about policy involving insurance, employment, access to education, and the like aimed at individuals? Or in the classical example, to screen potential immigrants? Will subtle or unsubtle pressure be imposed on those who would choose not to screen, on the grounds that their impaired offspring will be a burden on the health care system and hence on everyone? (That's a classic argument used by the original eugenics movement, and vigorously used in Germany to justify 'euthanasia' to countless thousands of 'defective' societal burdens)
These are issues we'll have to be facing in the future. And we don't need to raise the Nazi holocaust specter to see that they will be important. They involve both our concepts of genetic causation, our concepts of personal value, and in subtle ways our concepts of societal responsibility. There will be a great increase in the number of genetic variants that have high predictive power.
A lot of the eugenics movement in the last century, and even the rationale for the holocaust, was framed around evolutionary and Darwinian ideas. Nature eliminates the unfit, so why can't we help Nature out? If we don't, will our advanced medical and social-net system lead to the gradual pollution of the human gene pool? If so, it is not just the right of individual parents to decide, but society's, because society pays the bills economically and in terms of its abilities, for decreasing overall 'fitness'. These were the classic arguments. Is there a risk that renewed darwinian determinism--of some form specific to our time, not last century's, will lead society in similar directions?
These issues will not go away. But, in our next post, we'll raise important additional questions about what the impact of screening is in terms of the human gene pool, and what the impact on society of widespread personal eugenics might be.