On Monday, a group of U.S. scientists, The Center for Genetics and Society (CGS), and the activist group Friends of the Earth called for a global ban on gene editing of human embryos just a day before a major international meeting in Washington, D.C., to tackle the policy and ethical issues surrounding the technology.
On the surface, the practice could sound like a potential solution to a myriad of health problems facing the planet. Human gene editing would allow us to create “designer babies” by editing out undesirable strands of DNA. Supporters of the technique say it would allow future generations to be born without genetic predispositions to Alzheimer’s disease. 
Earlier this year in China, researchers reported they had used a gene-editing technique called CRISPR to modify an aberrant gene that causes an inherited, life-threatening blood disorder known as beta thalassaemia. The scientists utilized IVF embryos from obtained from fertility clinics. (They were not implanted in women following the experiment.)
Gene editing is fairly common in China, but scientists the world over worry about how the edits could affect generations to come, since those genetic alterations would be passed onto offspring. And, in theory, it could one day enable parents to “build” offspring with greater intelligence or athletic ability. 
“Like so many powerful new technologies, gene editing holds potential for both great benefit and great harm,” an open letter published by the groups said.
“The implementation of heritable human genetic modification — often referred to as the creation of ‘genetically modified humans’ or ‘designer babies’ — could irrevocably alter the nature of the human species and society.
“Gene editing may hold some promise for somatic gene therapy (aimed at treating impaired tissues in a fully formed person).
“However, there is no medical justification for modifying human embryos or gametes in an effort to alter the genes of a future child.”
Gene-editing techniques can be applied to non-reproductive cells to repair diseased genes, and this is not the source of the attendees’ primarily concern. The scientists object to “germline editing” in which reproductive cells, specifically, are edited.
The Obama Administration endorsed a ban on germline editing in May, saying more research was needed into ethical issues surrounding the practice.
Gene editing works similarly to the “find and replace” feature on a word processor. The gene to be edited is located and the edit is made either by deleting or repairing it. Genetic modification is ridiculously simple, thanks to modern technology.
In March, a group of scientists led by the key developer of CRISPR technology called on researchers to voluntarily ban the use of the technology on germline editing due to concerns over safety and eugenics. It wasn’t long after that that Chinese scientists reported carrying out the first experiment to alter the DNA of human embryos. The announcement sparked outrage, though some defended the Chinese scientists, saying the research was careful and safe since it was used only on non-viable human embryos.
For all of its promise, gene editing could prove to be a nightmare that could basically weaponized the human race, according to CGS executive director Marcy Darnovsky:
“The worst-case scenarios are pretty horrific: a genetics arms race between nations or within societies, a world in which affluent parents purchase the latest set of upgrades for their offspring, leading to the emergence of genetic ‘haves’ and ‘have nots’ … a world with new forms of inequality, discrimination and conflict,” she said.
 The Guardian
 ABC News AU