Indeed, some people are adamant that germ-line engineering is being pushed ahead with false arguments. That is the view of Edward Lanphier, CEO of Sangamo Biosciences, a California biotechnology company that is using another gene-editing technique, called zinc fingers nucleases, to try to treat HIV in adults by altering their blood cells. Weve looked at [germ-line engineering] for a disease rationale, and there is none, he says. You can do it. But there really isnt a medical reason. People say, well, we dont want children born with this, or born with thatbut its a completely false argument and a slippery slope toward much more unacceptable uses.

Critics cite a host of fears. Children would be the subject of experiments. Parents would be influenced by genetic advertising from IVF clinics. Germ-line engineering would encourage the spread of allegedly superior traits. And it would affect people not yet born, without their being able to agree to it. The American Medical Association, for instance, holds that germ-line engineering shouldnt be done at this time because it affects the welfare of future generations and could cause unpredictable and irreversible results. But like a lot of official statements that forbid changing the genome, the AMAs, which was last updated in 1996, predates todays technology. A lot of people just agreed to these statements, says Greely. It wasnt hard to renounce something that you couldnt do.

The fear? A dystopia of superpeople and designer babies for those who can afford it.

Others predict that hard-to-oppose medical uses will be identified. A couple with several genetic diseases at once might not be able to find a suitable embryo. Treating infertility is another possibility. Some men dont produce any sperm, a condition called azoospermia. One cause is a genetic defect in which a region of about one million to six million DNA letters is missing from the Y chromosome. It might be possible to take a skin cell from such a man, turn it into a stem cell, repair the DNA, and then make sperm, says Werner Neuhausser, a young Austrian doctor who splits his time between the Boston IVF fertility-clinic network and Harvards Stem Cell Institute. That will change medicine forever, right? You could cure infertility, that is for sure, he says.

I spoke with Church several times by telephone over the last few months, and he told me whats driving everything is the incredible specificity of CRISPR. Although not all the details have been worked out, he thinks the technology could replace DNA letters essentially without side effects. He says this is what makes it tempting to use. Church says his laboratory is focused mostly on experiments in engineering animals. He added that his lab would not make or edit human embryos, calling such a step not our style.

What is Churchs style is human enhancement. And hes been making a broad case that CRISPR can do more than eliminate disease genes. It can lead to augmentation. At meetings, some involving groups of transhumanists interested in next steps for human evolution, Church likes to show a slide on which he lists naturally occurring variants of around 10 genes that, when people are born with them, confer extraordinary qualities or resistance to disease. One makes your bones so hard theyll break a surgical drill. Another drastically cuts the risk of heart attacks. And a variant of the gene for the amyloid precursor protein, or APP, was found by Icelandic researchers to protect against Alzheimers. People with it never get dementia and remain sharp into old age.

Church thinks CRISPR could be used to provide people with favorable versions of genes, making DNA edits that would act as vaccines against some of the most common diseases we face today. Although he told me anything edgy should be done only to adults who can consent, its obvious to him that the earlier such interventions occur, the better.

Church tends to dodge questions about genetically modified babies. The idea of improving the human species has always had enormously bad press, he wrote in the introduction to Regenesis, his 2012 book on synthetic biology, whose cover was a painting by Eustache Le Sueur of a bearded God creating the world. But thats ultimately what hes suggesting: enhancements in the form of protective genes. An argument will be made that the ultimate prevention is that the earlier you go, the better the prevention, he told an audience at MITs Media Lab last spring. I do think its the ultimate preventive, if we get to the point where its very inexpensive, extremely safe, and very predictable. Church, who has a less cautious side, proceeded to tell the audience that he thought changing genes is going to get to the point where its like you are doing the equivalent of cosmetic surgery.

Some thinkers have concluded that we should not pass up the chance to make improvements to our species. The human genome is not perfect, says John Harris, a bioethicist at Manchester University, in the U.K. Its ethically imperative to positively support this technology. By some measures, U.S. public opinion is not particularly negative toward the idea. A Pew Research survey carried out last August found that 46 percent of adults approved of genetic modification of babies to reduce the risk of serious diseases.

Link:
Engineering the Perfect Baby | MIT Technology Review