vol. 353, i. 9167, page 1873

Abstract: Genetic manipulation of germ cells should be prohibited. Alterations of the genetic code in sperm cells, ova, and fertilized ova could be used to prevent disease or to induce desired traits. In comparison to gene transfer in other body cells, germ cell modification may produce effects that were not predicted, and may not reveal themselves until the child is grown, or in future generations. Germ cell modification not only influence the single offspring, but create unique DNA that will persist into subsequent generations. Prenatal diagnosis permits specific pregnancies to be evaluated for genetic fitness. Manipulation of germ-cell DNA is unnecessary and potentially dangerous.

Human germline gene modification has been foreseen but not yet accomplished.1-6 It can be defined as the genetic manipulation of human germ cells, or of a conceptus, resulting in inherited changes in DNA. With the development of advanced in-vitro fertilisation (IVF) methods, preimplantation DNA analysis, improved techniques for gene transfer, insertion, or conversion, and of embryo implantation procedures, the technical barriers to such an intervention seem easily surmountable. Unintended changes...