One of the most significant and yet controversial developments in genetic science in recent decades is the Human Germline Genetic Modification (HGGM) technology. By employing a set of techniques, scientists hope to be able to change the genetic composition of the human germline (i.e., eggs, sperm, the cells that give rise to eggs and sperm, or early embryo) for the benefit of future descendents who will inherit them.
The main purpose of HGGM is to ‘cleanse’ the gene pool of ‘deleterious’ and inheritable genes that would predispose people to certain diseases. This approach, according to some scientists, is to be preferred to traditional therapeutic strategies. For example, molecular biologist Daniel E. Koshland, Jr. could argue that ‘keeping diabetics alive with insulin, which increases the propagation of an inherited disease, seems justified only if one ultimately is willing to do genetic engineering to remove diabetes from the germline and thus save the anguish and cost to millions’.
The ultimate goal of HGGM is therefore to eradicate harmful genes responsible for diseases like cystic fibrosis from the whole population.
In this sense, HGGM must be distinguished from somatic cell therapy that involves the genetic modification of cells in the body apart from the reproductive cells. Somatic cell therapy treats the person with a genetic disease in a way that does not affect his or her offspring. While there is currently an international moratorium on HGGM, many countries in the world allow somatic cell therapy.
Although it is the intention of many scientists to use HGGM for therapeutic purposes, some are advocating that it should also be used to enhance certain desirable traits in the future generation. While many theologians and ethicists are opposed to this, the debate is complexified by the fact that the distinction between eliminating harmful genes and improving hereditary is very often blurred.
The main concern about HGGM is safety. Because these techniques edit the genetic makeup of the gametes, the changes inherited by future generations are deemed irreversible. Thus, the European Council for the Protection of Human Dignity states in its 1997 document that ‘Whilst developments in this field may lead to great benefit for humanity, misuse of these developments may endanger not only the individual but the species itself’.
Many scientists and ethicists maintain that it is simply impossible to envision the consequences of HGGM at this point. The debate sometimes gravitates to the question about the acceptable criteria for ascertaining whether it would be safe to proceed with HGGM. Although the current standard and protocol for research states that an intervention is considered adequate if it enjoys 70% success, some are arguing (for obvious reasons) that in the case of HGGM the requirement should be no less than a success rate of 100%.
In 1979, the influential philosopher and ethicist Hans Jonas in his remarkable book, The Imperative of Responsibility reminded us that in the midst of the tantalising progress of science and technology we must always pause to consider our responsibility to the future generation. The advance of science should not only fill society with a sense of hope, Jonas argues. It should also fill us with a sense of fear.
It is only when fear has its rightful place in our reflections on the promises of science and technology, he wisely counsels, that we will come to see that the ‘starry-eyed ethics of perfectibility has to give way to the sterner one of responsibility’.
Because the long-term adverse consequences of HGGM for future generations are not yet known or fully understood by scientists, and in light of the ethics of responsibility that Jonas emphatically advocates, both religious and secular institutions are opposed to the use of this technology on humans.
Dignitatis Personae, issued by the Roman Catholic Church in 2009, states that ‘Because the risks connected to any genetic manipulation are considerable and as yet not fully controllable, in the present state of research, it is not morally permissible to act in a way that may cause harm to the resulting progeny’.
This is echoed in a statement on HGGM issued by the United Methodist Church in 2012, which states quite categorically that ‘We oppose human germ-line therapies (those that result in changes that can be passed to offspring) because of the possibility of unintended consequences and of abuse’.
‘With current technology’, it continues, ‘it is not possible to know if artificially introduced genes will have unexpected or delayed long-term effects not identifiable until the genes have been dispersed in the population’.
In similar vein, the International Society for Stem Cell Research (ISSCR) calls for a moratorium on HGGM in a statement issued in 2015: ‘The ISSCR calls for a moratorium on attempts to apply nuclear genome editing of the human germ line in clinical practice. Scientists currently lack an adequate understanding of the safety and potential long-term risks of germ line genome modification’.
The call to acknowledge our responsibility towards future generations serves to remind us that no human being – present or future – should be excluded from our moral community or moral consideration. It must therefore be taken very seriously.