Edward Lanphier and colleagues contend that human germline editing is an unethical technology because it could have unpredictable effects on future generations. In our view, such misgivings do not justify their proposed moratorium (Nature 519, 410–411; 2015).
When in vitro fertilization and preimplantation genetic diagnosis were first introduced, they had unpredictable consequences. Both went on to transform reproductive medicine.
Many nations already have ethics review processes that assess the risks of experiments on human embryos, with the prospect of even stricter evaluation standards as new fertility techniques come along (I. G. Cohen et al. Science 348, 178–180; 2015).
There is no reason to close off whole avenues of controversial research when they have barely begun (see, for example, Nature http://doi.org/3xt; 2015). Germline editing is a revolutionary technology that potentially offers an enormous range of benefits to the next generation.