Germ line editing can be damaging

Several of the world's leading CRISPR scientists and bioethicists are calling for a global moratorium on editing human genes that can be passed on from parents to children.

In a new nature commentary published recently, Feng Shang and Emmanuelle Charpentier - two discoverers of the revolutionary CRISPR-Cas9 gene editing system - along with MIT biologist Eric Lander and 15 other researchers from around the world, outlined the urgent need to put a pause on the editing of sperm, eggs and embryos - known as the human germ line - to create genetically modified babies until countries agree on the best way forward.

These scientists were forced to write the sharply-worded article after China's He Jiankui revealed in November that he defied international norms and edited the DNA of three children, ostensibly to make them resistant to HIV.

There is no international framework as of now in which nations, while retaining the right to make their own decisions, voluntarily commit to not approve any use of clinical germ line editing unless certain conditions are met. The CRISPR research any way, would continue, including germ line editing for research that does not lead to modified babies, and editing nonheritable (somatic) cells to stamp of disease.

Their hope is to move the conversation beyond a focus on individual rogue actors, like He. There are some real questions going forward and those are about the decisions that countries make over the years and decades about which applications, if any, should be allowed. A framework is needed in place so that our children are proud of the decisions that get made, rather than thinking society moved forward thoughtlessly.

To begin with, there should be a fixed period during which no clinical uses of germ line editing whatsoever are allowed. Before such an editing is permitted, discussions about the technical, scientific, medical, societal, ethical and moral issues must be considered. This is not something that each and every society or each and every country would have to decide on its own. This debate is not about different society.

This is about mankind as a society. Right now, 30 countries, including the United States, have laws that either directly or indirectly prohibit germ line editing. But as CRISPR-Cas9 technology has made gene editing more accessible in recent years - allowing systems to edit, cut out, and replace genes in any living thing more quickly, cheaply and efficiently than previous gene editing tools, - scientists have been grappling with how best to proceed.

What baffles saner minds is whether we have really evolved to such an extent as to force a gene alteration when medical needs of man and social risks are still being debated. In December 2015, the organising committee of the first International Summit on Human Gene Editing at the national Academy of Sciences came out with a consensus statement on human gene editing.

The document reflected the excitement and wonder of this new technology, but also the researchers drew the line at clinical research that involves human germ line editing. We don't know the frontiers of this new knowledge and hence, we must not move ahead with germ line editing as we do not know how it will affect the future generations.