By Xinyi Gao
Preimplantation Genetics Diagnosis is a subsidiary of reprogenetics, which is a combination of types of approaches of genetics in human reproduction in order to eliminate certain genetic diseases or to obtain a desirable trait. However, preimplantation genetics diagnosis does not directly alter the genes of embryos, the technique is used to eliminate the risk of genetic disease in children of parents possibly carrying the gene for the specific disease. The technique is usually accompanied with in vitro fertilization. In vitro fertilization is a process which allows the embryo to be combined with an egg and a sperm in a laboratory outside of the human body.
Ever since in vitro fertilization was invented, preimplantation genetics diagnosis had been in use to detect potential genetic disorders in infants. In 1989, the first preimplantation diagnosis was used for sex selection to avoid fatal X-linked diseases. The procedure is often used for couples with the risk of having children with genetic diseases. For instance, if there is a family history of Duchenne muscular dystrophy, a progressive muscle degeneration disease which affects mostly males, female embryos can be chosen through screening to potentially avoid the disease.
The technique evolved from identifying embryo sex to identify single genes. And, by 2013, there are approximately 10,000 children born through preimplantation biopsies. Aneuploidy screening may also be implemented to ensure that there are multiple embryos transferred for parents with normal karyotypes, so that at least one of the embryos would survive eventually.
In 2008, a very controversial case of preimplantation genetic diagnosis involved more than two British couples screening for genes without the BRCA mutation hopefully to avoid breast cancer in the embryo. Nevertheless, having the mutation in the BRCA mutation only means that the individual is at the risk of developing the disease, the individual does not necessarily have to develop the disease. Although members of the Human Fertilization and Embryology Authority in Britain approved the case after lengthy debates, the case remained controversial. It is not flawlessly ethical to eradicate the risk of breast cancer from one’s lineage.
This case may open Pandora's box for future genetic modifications to achieve certain traits or manufacture extremely healthy embryos. The abuse of the technique may increase the differences between social classes and therefore, further societal problems. The practice of preimplantation genetic diagnosis should be restricted to fatal or genetic diseases with considerable negative impacts on children.
References
Coco R. (2014). Reprogenetics: Preimplantational genetics diagnosis. Genetics and
molecular biology, 37(1 Suppl), 271–284. https://doi.org/10.1590/s1415-
Green, R. M. (2008, April 13). Building Baby From the Genes Up. The Washington Post.
Pray, Ph.D, L. A. (2008). Embryo screening and the ethics of human genetic engineering.