Introduction
The book1 we will review in this paper is about the future developments in biotechnology, developments that have the potential to change fundamentally human reproduction. According to Henry T. Greely, simultaneous developments in stem-cell technology, gene sequencing/interpretation, and in vitro fertilization (I.V.F.) will usher what he calls Easy PGD. PGD (pre-implementation genetic diagnosis) is the genetic profiling of embryos before implementation. It is currently used during I.V.F. to detect possible genetic diseases. I.V.F. is the artificial fertilization of an egg with a sperm in vitro (in glass), and the implantation of the resulting embryo into the uterus of the biological mother or a surrogate. PGD requires I.V.F. Currently, PGD is not easy to implement because I.V.F. is an arduous process for women. Invasive procedures are used to retrieve the eggs, and women patients are required to undergo hormonal therapy to stimulate their ovulatory processes. On the other hand, despite enormous progress in genetic technology, gene sequencing is relatively expensive, and the interpretation of the genes (what kind of phenotype a certain genotype will produce) is not very effective. Greely believes that we will see enormous progress in the near future in stem cell and gene sequencing/interpretation technology, and these developments will render PGD cheap and easy to implement. They will transform PGD into Easy PGD. With Easy PGD, parents will be able to choose from a catalog of embryos their desired children. Greely, based on the statistics of planned pregnancies, unwanted pregnancies, present DNA screening ratios, etc., says that ten years after the availability of Easy PGD “somewhere between 60 and 70 percent of pregnancies in the U.S. will have been started using it.”2 And he adds that, “if the technology continues to be, and to seem, effective, that percentage should increase over time,” and “[…] in the long run, I could imagine 90 percent of U.S. pregnancies being the result of Easy PGD.”3
Easy PGD
Greely, to better explain the implications of these new technologies, describes DNA, genes, chromosomes, the mechanisms of inheritance, and the human reproductive system. We assume that the reader knows about these to read this review. Here, we only summarize Greely’s conclusions from his discussion of the human reproductive system. Greely thinks that the natural reproductive system is very complicated, prone to infertility, and susceptible to producing myriad forms of diseases. Many people are infertile because the human reproductive system is prone to a myriad of malfunctions like weak sperms, plugged fallopian tubes, the inability of embryos to hatch to the uterus, etc. The natural reproductive system produces various genetic diseases: heritable Mendelian genetic diseases, the errors in multiplying or transferring of genes during meioses (missing chromosomes, duplication or removal of some genes, etc.) These genetic diseases and errors often create debilitating syndromes. Greely sees the human reproductive system in its natural condition as an ineffective mechanism prone to errors.4 He thinks that we should improve it with artificial methods, and Easy PGD might be the final solution to the problems of the human natural reproductive system. It will not only solve infertility and genetic diseases, but it will also give humanity to control its own evolution by steering it to a desired pathway.5 How Easy PGD will function? Gametes (sperm and eggs) will be produced by stem cell technology from the cells that could be easily obtained, like skin cells. Using I.V.F., these gametes will be artificially fertilized to obtain a certain number of embryos. Embryos’ genes will be sequenced to determine their phenotypes. The embryos that have the desired phenotypes will be chosen to be implemented into the uterus of the genetic mother or a surrogate. For Easy PGD to become a reality, bioscientists should develop further the current technologies in three areas: stem cell technology, genetic sequencing, and interpretation of genes.
