NEW YORK • Scientists are now contemplating the fabrication of a human genome, meaning they would use chemicals to manufacture all the DNA contained in human chromosomes.
The prospect is spurring intrigue and concern in the life sciences community because it might be possible, such as through cloning, to use a synthetic genome to create humans without biological parents.
While the project is still in the idea phase, and involves efforts to improve DNA synthesis in general, it was discussed at a closed-door meeting last Tuesday at Harvard Medical School in Boston. The nearly 150 attendees were told not to contact the media or post on Twitter during the meeting.
Organisers said the project could have a big scientific payoff and would be a follow-up to the original Human Genome Project, which was aimed at reading the sequence of the three billion chemical letters in the DNA blueprint of human life.
The new project would involve not reading, but rather writing the human genome - synthesising all three billion units from chemicals.
But such an attempt would raise numerous ethical issues. Could scientists create humans with certain kinds of traits, perhaps people born and bred to be soldiers? Or might it be possible to make copies of specific people?
"Would it be okay, for example, to sequence and then synthesise Einstein's genome?" Dr Drew Endy, a bioengineer at Stanford University, and Dr Laurie Zoloth, a bioethicist at Northwestern University, wrote in an essay criticising the proposed project. "If so, how many Einstein genomes should be made and installed in cells and who would get to make them?"
Dr Endy, though invited, said he deliberately did not attend the meeting at Harvard because it was not being opened to enough people and was not giving enough thought to the ethical implications of the work.
Dr George Church, a professor of genetics at Harvard Medical School and an organiser of the proposed project, said there had been a misunderstanding. The project was not aimed at creating people, just cells, and would not be restricted to human genomes, he added.
Rather it would aim to improve the ability to synthesise DNA in general, which could be applied to various animals, plants and microbes.
"They're painting a picture which I don't think represents the project," Dr Church said.
Scientists and companies can now change the DNA in cells, for example, by adding foreign genes or changing the letters in the existing genes. This technique is used to make drugs, such as insulin for diabetes, inside genetically modified cells, as well as to make genetically modified crops.
And scientists are now debating the ethics of new technology that might allow genetic changes to be made in embryos. But synthesising a gene, or an entire genome, would provide the opportunity to make even more extensive changes in DNA.
NEW YORK TIMES