by Gene Turnbow
Genetically modified humans have been a staple in science fiction for decades, but now researchers at the Institute for Reproductive Medicine and Science of St. Barnabas in West Orange, New Jersey say that it’s already happened.
They’re saying that about 30 children born as a result of a fertility experiment are carrying mitochondrial DNA from a third parent. The main DNA from the two original parents is intact, but the mitochondrial DNA (which is separate) contains sequences from a second woman, genes that were added in the laboratory in an effort to produce a viable human egg. Writing in the journal Human Reproduction, the researchers, led by fertility pioneer Professor Jacques Cohen, say that this ‘is the first case of human germline genetic modification resulting in normal healthy children’.
In each of the 30, something in the mother’s egg had prevented her from conceiving naturally. So far, only two of the babies have been tested and have been found to contain genes from three ‘parents’, but the potential is there for another 28. Fifteen of these children were born in the past three years. The fact that the children have have inherited the extra genes and incorporated them into their ‘germline’ means that they will, in turn, be able to pass them on to their own offspring. Altering the human germline – in effect tinkering with the very make-up of our species – is a technique shunned by the vast majority of the world’s scientists. The concern is that one day this method could be used to create new races of humans with extra, desired characteristics such as strength or high intelligence. It should be clear that the intent here was not to create superhumans, but to correct a technical problem with the mitochondria in the human eggs that prevented conception.
Jacques Cohen is regarded as a brilliant but controversial scientist who has pushed the boundaries of assisted reproduction technologies. He developed a technique which allows infertile men to have their own children, by injecting sperm DNA straight into the egg in the lab. Prior to this, only infertile women were able to conceive using IVF. Last year, Professor Cohen said that his expertise would allow him to clone children –a prospect treated with horror by the mainstream scientific community.
‘It would be an afternoon’s work for one of my students,’ he said, adding that he had been approached by ‘at least three’ individuals wishing to create a cloned child, but had turned down their requests.
The different genes come from DNA contained in mitochondria — little organs inside cells that create the energy to do life’s work. They contain DNA — only about 0.03 percent of the total DNA — so they can make copies of themselves when cells divide. The other 99.97 percent of a cell’s DNA comes from the nucleus and the 23 pairs of chromosomes.
In this case, no arcane hocus pocus was used – they simple sucked some mitochondria out of healthy eggs and injected them into eggs that would ordinarily be nonviable. The cell’s primary DNA wasn’t touched. Still, the germline has been directly modified, and some are calling Dr. Cohen a demon, going so far as to paint little horns and a handlebar mustache on him and posting their complaints on the web. In this case, no harm was done – and it’s a very long leap from swapping out some broken parts to intentionally modifying specific sequences in the human genome to produce specific modifications or improvements. If that starts happening, we will be then directly tinkering with what makes us human.
While this is an interesting milestone, we haven’t created Khan Noonien Singh. Clearly, as a species, our reach has always exceeded our grasp, and it will be possible to actually do such a thing long before we have assessed whether or not it is wise to do so.
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