In our January article on hot trends in biomedical engineering for 2014 [1], we predicted the CRISPR/Cas system to become a transformative and powerful tool for gene editing. The simplicity, precision, speed, and low cost by which one or more gene sequences can be selectively silenced, enhanced or changed with CRISPR is truly remarkable and is at the forefront of the nascent revolution in the ability to purposely and easily transform the genetic information of an organism. After learning about CRISPR, I thought it would be several years before applications in human reproduction emerged. I was wrong. Researchers in China have moved that possibility much closer as reported recently in the MIT Technology Review. Surprisingly, it has only been 40 years since the birth of the first human, Louise Brown, conceived by in vitro fertilization (IVF) so in less than a lifetime the frontiers of reproductive health will be radically expanded and redefined. What are the implications of these new genetic capabilities and what are the possible unintended consequences?
MIT Technology Review reported in April 2014 [2] on the application of CRISPR by Weizhi Ji and his team of scientists at Kunming Biomedical International and its affiliated Yunnan Key Laboratory of Primate Biomedical Research to make targeted genetic modifications in primates with the goal of creating nonhuman primate models of complex human diseases such as neurological or metabolic disease. In these experiments, three different genes in in vitro fertilized eggs were modified by CRISPR and implanted in a surrogate macaque mother who gave birth to twin sisters carrying the same genetic modifications. An intriguing aspect of the work is that the Kunming team has suggested the possibility that CRISPR could be applied to alter human fertilized eggs and that such eggs could grow to be genetically modified babies, posing new ethical dilemmas.
Alexis Madrigal writes in a separate but related article in the June issue of The Atlantic monthly [3] on how the birth of Louise Brown, the first child conceived through IVF, heralded a revolution in the mechanics of human reproduction and how we view and understand the nature of reproduction. Clearly IVF has changed many lives for the better by allowing infertile couples to have biological children, but many at the time were concerned with the unintended consequences of the technique. Indeed, James Watson predicted that if IVF were allowed to proceed on a broader scale that “all hell will break loose, politically and morally, all over the world.” Most notably that didn’t happen but it brings into focus the many complex moral and ethical issues when it becomes possible to manipulate the process of human reproduction to a particular end.
Madrigal highlights five future reproductive innovations drawn from interviews with scholars, doctors, and entrepreneurs as likely outcomes of current trends in the application of reproductive technologies that may change the future in how a person is made and the very definition of a family. Of particular interest to me was her last innovation where she points out the increasing ability to screen IVF embryos and select out those with inherited genetic disease mutations. Several major medical centers such as Johns Hopkins and the NYU Fertility Center offer preimplantation genetic diagnosis and screening services to test an embryo for a specific genetic disease it is at risk of inheriting from the parents. Clearly this is of tremendous health benefit to the unborn child but as our ability to collect and interpret genetic information increases, why would we not deselect embryos for other undesirable genetic traits? And in combination with CRISPR, why not simply engineer the embryo genome to delete those traits deemed undesirable and insert those preferred by the parents? Not surprisingly active areas of genetic research include understanding the genetic underpinnings of high-order traits such as intelligence. Indeed the Beijing Genetics Institute (BGI) is one institution at the forefront with the BGI Cognitive Genomics Lab founded in 2011 to conduct interdisciplinary research in this area.
The rapid advances in our ability to read and rewrite an embryo’s genetic code are extremely powerful and have tremendous potential for diagnosis and treatment of complex human disease; yet they also have the potential to fundamentally change how we view ourselves and what it is to be human. With knowledge comes a collective responsibility, and, as biomedical engineers and scientists inventing and applying these powerful genetic technologies, we must lead an informed dialogue with our colleagues, political leadership, and the public on the moral and ethical consequences of their application.
References
- S. Fischer. (2014, Jan.). Forecast 2014, IEEE Pulse, 5(1), pp. 18–27. [Online].
- C. Larson and A. Schaffer. (2014, Apr. 23). Genome editing: The ability to create primates with intentional mutations could provide powerful new ways to study complex and genetically baffling brain disorders. MIT Technology Review. [Online].
- A. C. Madrigal. (2014, May 21). Making babies: Five predictions about the future of reproduction. The Atlantic. [Online].