Playing God With DNA Doesn’t Work

One of the promises of modern genetics is that in the future, we will create “designer babies.” The idea is that if you produce a group of embryos and then look at the DNA of each of them, you can select which embryo you want to become your child. The other embryos would be destroyed. The process is called “preimplantation genetic diagnosis (PGD).” You might call it playing God with DNA.

With PGD, the embryos are created through in vitro fertilization. Technicians remove a single cell from each embryo and test it for single-gene variants which cause cystic fibrosis, Tay-Sachs, or other diseases. Many diseases such as diabetes may result from variants in hundreds or thousands of genes. The risk for heart disease may involve millions of gene variants.

Medical scientists are working to establish a polygenic score, which would indicate intelligence, height, and other traits by examining the DNA. They call these factors “enhancements.” The problem is that those traits may also be the result of multiple genetic variants. Playing God by trying to select the attributes for a “designer baby” can be not only immoral but dangerous.

A group of researchers published a study in the journal Cell on November 21, 2019, in which they attempted to learn how reliable polygenic scores would be for determining height or IQ. The research indicates that the DNA genetic predictions about those enhancements are unreliable and insignificant at best. Among other problems is that “differences in diet, lifestyle, exposure to pollution, culture, undiscovered genetic variants, and other unknown factors can influence how complex traits develop.”

The original use of polygenic scores was to help people know if a lethal or disruptive disease was a part of their heredity. Being able to repair the DNA or choosing not to have children is an option that would be useful to couples. Embryo selection for non-medical traits such as height, intelligence, or gender is a whole different question.

An article on this study in ScienceNews.org quoted Dr. Nicholas Katsanis, who is a human geneticist at the Lurie Children’s Hospital of Chicago. Dr. Katsanis said, “The idea that we’re going to do genetic screening for anything other than medically actionable items is the definition of eugenics. That we’re even contemplating this is disturbing.”

We agree that humans playing God in areas like this is immoral and likely to be disastrous at worst and disappointing at best.

— John N. Clayton © 2019