This guy is probably a bullshit artist . . .

. . . but it doesn't much matter because this will happen soon anyway. Chinese researcher He Jiankui claims he used the CRISPR method to edit the DNA of seven human embryos, two of which have no been brought to term. I have discussed this method before. It uses a mechanism derived from prokayrotic cells to make precision changes to a genome. This makes genetic engineering far more feasible.

He says the parents refuse to be interviewed and he won't say where this was done.  What he claims to have done specifically is to introduce an edit to the gene that codes for CCR5, a receptor that is essential to the means by which HIV gets into T cells. This would make the children resistant to HIV infection.

The specific action seems unjustifiable in itself. We know how to protect children and adults against HIV, and this mutation (which is rare but does exist in nature) doesn't just protect against HIV, it makes the immune system less competent against some other viruses. The receptor exists for a reason. (Of course HIV has not existed previously in our evolution.)

That aside, this method doesn't just change some cells in the resulting organism. It changes every cell in the body including germ line cells, which means that the change will be passed on to future generations. In this instance the children's children will have it, and so will their children and grandchildren, at least heterozygously. By that time HIV may have been eradicated for all we know, or there may be an effective vaccine, making the change wholly detrimental.

Furthermore, CRISPR isn't perfect. Sometimes it hits nucleotides other than the target. That's why the consensus among researchers in this area is that it is unethical to use it at this time even to correct genetic diseases -- there could be unanticipated consequences. But let's project ourselves into the future, when presumably it will be possible to use the technique with high assurance of accuracy. That would enable people with homozygous genetic defects to have healthy children. Few people will object to this, although of course it does involve in vitro fertilization and discarding of some embryos, probably many.

The big problem is that it will most certainly not stop there. Some rich person will hire He or one of his colleagues to create a designer baby, maybe with a genetic predisposition to height, high IQ, you name it. We don't yet have a good idea how to create such predispositions -- they are the result of interactions among innumerable genes, usually not a single one; and the phenotype -- the developed organism -- will depend on the interaction of genes with environment. Nevertheless, we presumably will learn more about this and it will be possible to create the right environment for the desired phenotype to emerge.

This genie is not going back into the bottle. Genetically enhanced humans have long been a subject of science fiction. The usual scenario is that they are illegal, but I suspect some people think this is  good idea. This is a discussion we need to be having.