Genetics is the determinism of our age (“Your destiny is determined by your genes”). It appears more scientific than the determinisms of previous ages such as astrology (“Your destiny is in the stars”) or Marxism (“Your destiny is in economics”), and thus has much greater appeal to the people who look to science for The Answers. News headlines breathlessly report the discovery of the “gene for” this behavior or that behavior: the gene for losing your virginity early, the gene for adultery, the gene for lying. What the headlines leave out are the subtleties: yes, our genetics have an influence our behaviors and decisions, but they are not “determinative” in any sense that that word is commonly understood. The same holds true for the genetics of many diseases: genes for things like diabetes and heart disease and high blood pressure and even breast cancer can increase or decrease the likelihood that someone will develop that disease, but are not “determinative.” Many, many factors other than genetics also play a role in developing these diseases.
However, there are some diseases for which the genes do seem to be determinative; that is, if you have certain genes for a condition, you will inevitably develop that condition. Such genetic disorders are called “fully penetrant.” In these cases, destiny does seem to be in the genes . . .
Or maybe not? In a study published earlier this month in Nature Biotechnology, researchers combed through 589,306 genomes obtained from genomic databases such as 23andMe. In so doing, they found thirteen people who have the genes for eight fully-penetrant, usually lethal, childhood-onset disorders; but the adults with those genomes are healthy adults, without the disorders their genes code for.
Granted, thirteen out of 589,306 isn’t a lot. But extrapolate that to seven-plus billion people on the planet, plus all the fully-penetrant genetic conditions these researchers did not check for, and there are probably a lot of what the press calls “genetic superheroes” among us. In fact, this study is part of something called “The Resilience Project,” which aims to find a lot more people like these thirteen and figure out what makes them “resilient,” that is, able to carry fully-penetrant genes for lethal diseases without carrying the diseases themselves. In line with the reigning biogenetic paradigm, the project’s focus is searching for other genes that make these people resilient by canceling out the bad-disease genes. Maybe they will find them, and if so, be able to help those people with those diseases. But if not, I hope that they will also look outside of the genetic determinism paradigm for non-genetic factors; I hope that they will consider the possibility that we may not be simply the product of our genes.
This study should give us a great sense of humility that, despite wonderful advances in our understanding of the wonder of genetics, there is probably more that we don’t understand about how genes work than we do understand. This humility should lead us to question anyone who would attempt to efface our humanity or responsibility for our actions on the basis of an appeal to genetic determinism. And it should call into question the practice of using any genetic test, preimplantation or post-implantation, as the basis for deciding whether a human embryo or fetus lives or dies.