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Lots of children have three parents.  A boy’s mother and father might divorce, and one remarries.  A girl might be raised by a single mother, a cousin, and an aunt.  But everybody, without exception, has two biological parents. For the moment, at least.


The United Kingdom is on the verge of permitting scientists to move forward with a procedure to create a human child from the DNA of three adults.  The United States may not be far behind.  Mothers everywhere should be deeply concerned.


The procedure, called mitochondrial replacement (MR), would combine genetic material from the eggs of two different women to create a newly-constructed egg, which would then be fertilized by sperm – creating, for the first time in human history, a child with three biological parents.


According to researchers, this would be done for therapeutic purposes to help women with certain mitochondrial defects avoid passing on those defects, which can cause damage to the heart, liver, brain, and kidneys, among other parts of the body.  Damaged DNA of the mother-to-be would be replaced by the healthy DNA of another woman.  But here’s the tricky part: the genetic changes would show up in every cell of a child born after such a procedure. Not only that: they would be passed on to all descendants of the girls in whom the change is made. MR is a form of germ-line engineering, or inheritable genetic modification, and it involves manipulating genes to try to determine the traits of future children.


If allowed, inheritable genetic modification could open the door to the creation of “designer babies,” and even a Gattaca-like world of genetic “haves” and “have-nots.” Scientists could try to manipulate genes not only to avoid the transmission of certain diseases, but also to determine hair, eye, and skin color, IQ, height, weight, athletic prowess, and other traits.


We are in the midst of a biotechnological revolution that could result in treatments for many diseases that are now incurable.  That’s wonderful news.  But some of the same techniques that might help rid us of certain diseases could also be misused to create human clones, make “designer babies,” and introduce entirely new forms of inequality into the world.  Some people who promote the use of  inheritable genetic modification actually embrace these prospects, and look forward to a “post-human” future with different sub-species of humans – and the end of our common humanity.


As a mother, I understand and I empathize with women who want to avoid transmitting dreaded diseases to their children. The problem is that mitochondrial replacement is a biologically extreme technique that raises serious issues of safety and efficacy, and social and ethical challenges with profound implications for the human future.  And there are far safer ways of helping women with mitochondrial defects have healthy children, including embryo-screening before pregnancy, and egg donation.


Because inheritable genetic modification could fundamentally alter the human species, more than 40 countries and several international charters have prohibited it.  Unfortunately, the United States has not yet joined in this emerging global consensus.


One of the many troubling aspects of the potential use of mitochondrial replacement is how little public attention it has drawn. This technology is of profound significance to all of us, but there has been limited public awareness or dialogue about it. So far, the debate has been dominated, as so often, by scientists, entrepreneurs, and policymakers.  As usual, the people most affected by change are those whose voices are least likely to be heard. That’s why a continued moratorium on the use of mitochondrial replacement procedures would be a good thing.


All of us need time to get a handle on this technology and its implications for us and for our children.  The profound and urgent questions raised by the possibility of human inherited genetic modification especially demand the attention of mothers.  We are, after all, talking about making a break with human reproduction as we have known it for all of human history.


The first step is to inform ourselves – and fast. Things are moving quickly. The second step is to realize that while the technology may be new, it presents age-old dilemmas of freedom and limits, individuality and community, equality and fairness. It would be wrong for either the United Kingdom or the United States to move forward on this technology without hearing what mothers have to say.


For more information:

Mothers for a Human Future

Center for Genetics and Society

Tinkering with DNA


Enola G. Aird is the founder and director of Mothers for a Human Future (MHF), a nonprofit initiative working to preserve our humanity in the face of forces that are pushing us toward what has been called the “post-human” future. MHF is especially focused on promoting awareness, advocacy, and activism about human biotechnologies that could alter the human species.

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