This conditioning effect continues and increases after birth, leading to different degrees of epigenetic marking in different organs. Individual differences in susceptibility to diseases can be the consequence. This is nicely illustrated in identical twins, who show as they age increasing differences in the way that their identical DNA is marked by the environment.
Nonetheless, the dangers implied by recent technological progress have become increasingly obvious. For example, it is now possible to analyze the DNA of an unborn child from the blood of its mother and determine its risk for diseases later in life. This opens the door to full-blown eugenics: the selection by parents, authorities or others of children with characteristics considered “appropriate.”
We must take care that we do not become more fascinated by the composition of DNA and what characteristics and risks it carries than we are by the human qualities of less-than-perfect individuals, which we all are.
This does not mean that there are no applications of this knowledge that are not important, life-saving and even necessary. However, they are more limited in number and scope than many seem to believe. Now is a time not only to advance current research in this area, but also to reflect and to tread cautiously.
Jean-Jacques Cassiman is a professor of human genetics at the Center for Human Genetics at the Catholic University of Leuven, Belgium.
Copyright: Project Syndicate