Rebecca Taylor is guest blogging here this month. Rebecca is a Technologist in Molecular Biology, MB(ASCP) and a practicing Catholic. She has been writing and speaking about Catholicism and biotechnology for five years at her blog Mary Meets Dolly. This is her fifth and final installment.

Last week’s guest blog was all about the distinction between gene therapy and genetic enhancement. This week I want to delve deeper into the world of human genetic engineering and discuss somatic and germ-line genetic modifications. I know that for some of you the words "somatic" and "germ-line" have made your eyes glass over and I am about to lose you (if I haven’t already). Stick with me! This will not be as painful as it sounds and you might actually enjoy knowing more about human genetic engineering than 99.9% of the general populace

This week’s distinction between somatic and germ-line modifications is just as important as the distinction between gene therapy and genetic enhancement. Somatic is a fancy scientific term meaning any cell that is not a reproductive cell like an egg or sperm. Somatic cells are heart, lung, muscle, brain cells and the like. Germ cells are the reproductive cells, namely egg and sperm. A somatic genetic modification is a genetic modification that is in the somatic cells only. So a somatic genetic modification is one that does not extend to the germ cells and so will not be inherited by any future offspring. A germ-line genetic modification is one that is made so that it is included in the germ cells. Germ-line modifications will be inherited which means that the genetic engineering will be passed on to future generations.

Currently, a germ-line genetic modification would be accomplished by modifying a sperm or egg before IVF so the resulting embryo has the modification or modifying an existing IVF embryo before implantation. The idea is to modify the human organism early enough in development that the modification is in all the cells including the germ cells. That way when that embryo becomes and adult, its sperm or egg contain the modification and so that adult will pass that genetic alteration on to his or her offspring.

So what does the Catholic Church say about somatic and germ-line genetic modifications? Somatic modifications for gene therapy is morally permissible. In plain English that means genetically modifying one person to cure disease is great. As discussed before, a somatic genetic enhancement, taking one person and enhancing them beyond what is human, is never moral and should never be attempted.

But what about germ-line modifications? In theory, the Church embraces germ-line gene therapy. If curing genetic disease in one patient is good, then curing the disease for the whole family for every generation after is even better. The problem is that as current technology stands, to make the germ-line modification means that a human life has to be created and manipulated in a lab dish. The Catholic Church rejects the creation of human life in a lab. Once technology is developed that will allow the germ-line gene therapy to be accomplished without IVF or cloning and can be shown to be safe without major side effects, then the Catholic Church can embrace it. So while germ-line gene therapy is not now moral, it could be in the future.

As for germ-line genetic enhancement, if genetic enhancement is immoral for one individual, it is certainly immoral if it is done to every generation that follows. A germ-line genetic enhancement means that children, grandchildren, great grandchildren and so on will also be enhanced. This is the granddaddy of all unethical human genetic engineering. It is one thing to enhance yourself, it is quite another to force it onto generations that never asked for it.

Libertarians are some of the greatest advocates for the germ-line genetic enhancement. They believe it is their right to enhance their offspring in any way they see fit and anyone telling them otherwise is forcing their ideals on others. The argument can be summarized by Ronald Bailey in his piece for Reason magazine:

Liberals accept as true that there is a protected sphere of private activity and belief into which even well-meaning democratic majorities may not intrude. Biotechnology is one of a suite of new intimate technologies which are well on the way to empowering people to enhance themselves and their progeny by giving them stronger bodies, longer and healthier lives, and smarter brains. Certainly technologies dealing with birth, death, and the meaning and purpose of life need protection from meddling by others who, however democratically, would force their visions of the good on the rest of us.

Bailey’s argument seems compelling but, like most people these days, he is only thinking about the rights of the PARENTS and not of the resulting children and grandchildren. He argues that telling parents they cannot genetically enhance their offspring is forcing our "visions of good" on them. I argue it is the parents who would genetically enhance their progeny that are forcing "their visions of the good" on their children. Children who are genetically enhanced to be intelligent or athletic would be forced to fit their parents’ idea of genetic perfection. And not just while the children are minors, but for the rest of their lives. Enhancement is not like piano lessons or sport that a child can quit once out of the house, it is for life. And if it is a germ-line enhancement, these children will be unable to help passing this parental "vision" on to their children and their children’s children. Talk about forcing one’s ideals on other people. In reality, germ-line genetic enhancement is the exact opposite of a liberal ideal.

So what is the current state of genetic engineering in humans? Right now most genetic engineering is being attempted only at the somatic level for gene therapy. The attempt is to cure disease and only in the somatic tissues that are affected in a specific patient. This means that the genetic modification is only for the person who needs it and will not be passed on if that patient has children. Unfortunately, somatic gene therapy has had some pretty terrible side effects including cancer and death. The gene therapy was only undertaken because the risk of the genetic engineering was outweighed by the devastation of the genetic disease. With the risks inherent in genetic engineering, genetic enhancement of an otherwise health individual is downright dangerous, and germ-line genetic enhancement of future otherwise healthy individuals is morally unthinkable.

Congratulations, you are now more educated about human genetic engineering than 99.9% of the general populace. Pat yourself on the back.

Now it is up to you to educate your friends and family. To control human genetic engineering BEFORE it controls us we need to listen to the wisdom of the Church and make the distinction between gene therapy and genetic enhancement and be mindful of the differences between somatic and germ-line modifications. Widespread human genetic engineering is not yet a reality, but someday it will be. And it falls on us to make sure that it doesn’t destroy our humanity. Luckily we have the teachings of the Church to guide us.

I want to extend a warm thank-you to Matthew and Patrick Archbold for letting me write at you for 5 weeks in a row. Thank-you gentlemen for giving me this opportunity to spread the wisdom of our Church!


Matt here again. Rebecca writes at Mary Meets Dolly which is, literally, the meeting of the world of genetics and genetic engineering, represented by Dolly, “mother” of modern biotechnology, and the teachings of the Catholic Church on the sanctity of life, represented by Mary, mother of Christ and the Church. Rebecca started www.MaryMeetsDolly.com to help everyday Catholics better understand the science and ethics surrounding modern biotechnology in light of Catholic Church teaching. Please Check her out.